diff --git a/frontend/README-tcltk b/frontend/README-tcltk
index e6c3c384..2b499d96 100644
--- a/frontend/README-tcltk
+++ b/frontend/README-tcltk
@@ -24,16 +24,38 @@ See man xorriso for a documentation of xorriso concepts and commands.
 See man xorrecord for details of the burn image file feature.
 
 
-Quick start:
+                             Quick start
 
-  xorriso -launch_frontend $(which xorriso-tcltk) --stdio --
+In the xorriso build directory, without installation of xorriso:
 
+  xorriso/xorriso -launch_frontend frontend/xorriso-tcltk --stdio --
+
+After installation of xorriso by make install:
+
+  xorriso-tcltk
+
+
+                            Overview of GUI
+
+The window is separated into three main areas:
+- Connection to xorriso.
+- Management of drives and image files.
+- Inspection, manipulation, and exploitation of xorriso ISO image model.
+
+Click the rightmost mouse button while being over any of the GUI elements
+in order to get the particular help text for that element.
+There is no need to close the help window. Just click another element to
+get another help text.
+
+
+                         Program start options
 
 The Tcl shell "wish" is allergic to options which start by "-h".
 So here is the output of  xorriso-tcltk --help :
 ------------------------------------------------------------------------
+
 Usage:
-  xorriso-tcltk [options]
+  frontend/xorriso-tcltk [options]
 Options:
  All options must be given with two dashes ("--option") in
  order to distinguish them from any options of the Tcl shell.
@@ -51,6 +73,9 @@ Options:
      It is important that the parent of xorriso and of this
      tcl/tk frontend opens the named pipe for commands before
      it opens the named pipe for replies. This avoids deadlock.
+ --silent_start
+     Do not issue the start message xorriso-tcltk-version.
+     This works only if --silent_start is the first argument.
  --geometry {+|-}X{+|-}Y
      Sets the position of the main window.
  --click_to_focus
@@ -63,229 +88,12 @@ Options:
      Set a file address for logging of xorriso commands and
      reply messages. The log lines will be appended.
 
-Either --stdio or --named_pipes must be given for a program run.
+If neither --stdio nor --named_pipes is given, then this script
+will try to locate itself in the filesystem and start a xorriso
+run that launches it again.
+
+In the running GUI, click with the rightmost mouse button on
+any GUI element to get its particular help text.
 
 ------------------------------------------------------------------------
 
-
-                         Overview of GUI elements
-
-The window is separated into three main areas:
-- Connection to xorriso.
-- Management of drives and image files.
-- Inspection, manipulation, and exploitation of xorriso ISO image model.
-
-------------------------------------------------------------------------
-
-                         Connection to xorriso
-
-The "End" button leads to the end of frontend and xorriso process.
-
-The ready/busy field indicates whether a xorriso command is being executed
-and the frontend is still waiting for its reply messages.
-
-The "Command:" field can be used to send commands to xorriso.
-
-The "Refresh state display" button causes the other two main areas to update
-their display after manually transmitted commands may have changed the state
-of drives or ISO model.
-
-The "Log pipes" switch controls whether all xorriso commands and replies
-shall be logged to standard error resp. to the file that has been iven
-with program argumen --log_file. Caution: This log is verbous.
-
-The message box displays commands sent to xorriso and messages recieved
-from xorriso.
-Many commands which are emitted by the GUI will hide themselves and their
-replies from this display.
-All event messages with severity WARNING or higher will show up, nevertheless.
-
-The "Recent problem:" field shows the most severe event message that occured
-during the execution of the most recent command. It also displays the most
-recent problem message from the frontend program itself.
-Several commands emitted by the GUI will not clear this display. But any
-manually transmitted command and the major GUI gestures will do.
-
-The "Worst problem:" field shows the most severe event message that occured
-since last time the "Clear" button was hit. It will not clear automatically.
-
-
-------------------------------------------------------------------------
-
-                    Management of drives and image files
-
-The "Scan for drives" button executes command -devices and puts the list
-of found optical drives into the box underneath the button.
-
-The "Pick input drive" button executes command -indev and obtains some
-information about the medium status. This info is displayed in the 
-"Input drive or image" line.
-Further it causes the display of the ISO image model to be updated.
-
-The "Pick output drive" button executes command -outdev and displays the
-related info in the "Output drive or image" line.
-
-The "Pick drive for both roles" button executes command -dev and displays
-info in both "... drive or image" lines.
-
-The "Give up drives" executes commands -indev "" -outdev "" and clears
-both "... drive or image" lines, as well as the ISO model.
-
-The "Calm drives" button executes command -calm_drives which tells the
-aquired optical drives to stop spinning until the next drive activity
-gets triggered.
-
-The "Rollback" button excutes command -rollbackwhich drops all pending
-changes of the ISO model and reloads it from the input drive, if one is
-aquired.
-
-The box underneath these buttons shows the optical drives found by the
-"Can for drives" button.
-A double-click on a drive item has the same effect as button "Pick drive
-for both roles".
-
-The line "Input drive or image" displays address and medium status of
-the input drive.
-Its "Eject" button excutes command -eject "in".
-Editing the drive address and pressing the Return key causes the execution
-of command -indev with the field content as drive address. Use this to
-load the model from ISO image data files on hard disk.
-
-The line "Output drive or image" does about the same for the output drive.
-The text input field can be used to address an existing ISO image data
-file or to address a data file that does not yet exist. In the latter
-case, the ,edium status will be blank.
-
-The "Blank" button executes command -blank "as_needed" on the output drive.
-This also applies to ISO image data files, which will get invalidated by
-a small write operation.
-
-The "Format" button executes -format "as_needed".
-This only applies to real optical drives and s of interest only with DVD-RW
-or BD-R media, which both can be used formatted and unformatted. Other media
-types which mandatorily need formatting will be formatted by the write
-commands.
-
-The "Write ISO session" executes command -commit, which writes a session
-with all pending changes to the output drive. The output drive must be
-either blank or it must be the same as the input drive.
-
-The "Close" switch controls whether command -close "on" is emitted with
-"Write ISO session" or whether -as cdrecord option -multi is omitted with
-"Burn image file:".
-
-The "TAO" switch controls whether an incremental write type shall be
-enforced with write commands. Normally xorriso will decide by medium status
-and job parameters which write type to choose.
-
-The "Defect Mgt" switch controls whether slow and error-prone drive internal
-check reading shall be enabled with formatted BD-R or with BD-RE.
-
-The "Burn image file:" button executes command -as "cdrecord" with the
-content of its text field  as disk file address of a data file that is
-to be written to the output drive.
-The medium in the drive may be blank or appendable.
-
-
-------------------------------------------------------------------------
-
- Inspection, manipulation, and exploitation of xorriso ISO image model
-
-The "Extract to disk:" button executes command -extract with the whole
-tree of the current ISO directory or with the selected items of the box
-underneath "ISO directory:".
-This copies the selected files or directory trees from the input drive
-to the address on hard disk which is given by the text filed right of
-the button.
-
-The "Underneath" switch controls the effective hard disk address of an item
-if the address in the text field points to a directory. If "Underneath"
-is enabled, then the file object from the ISO filesystem will be copied to its
-name underneath the hard disk directory.
-If "Underneath" is disabled then an ISO directory tree item will be merged
-with the disk directory tree at the given address.
-Example:
-Selected are "/iso_dir" and "/iso_file".
-Address for hard disk is "/tmp/from_iso". Switch "Selected" is enabled.
-"Underneath" enabled causes commands:
-  -extract /iso_dir /tmp/from_iso/iso_dir 
-  -extract /iso_file /tmp/from_iso/iso_file 
-"Underneath" disabled:
-  -extract /iso_dir /tmp/from_iso
-  -extract /iso_file /tmp/from_iso
-The last command will fail because /tmp/from_iso already exists as directory.
-
-The "Selected" switch controls whether the whole current ISO directory,
-or only the selected items shall be copied to to hard disk.
-
-The "Overwrite files" switch controls whether existing files may be
-overwritten in the ISO image or by extraction on hard disk.
-The frontend program will only detect the most obvious name collisions,
-but xorriso will reliably refuse to overwrite files if this is banned.
-
-The "Overwrite ISO dirs" switch controls whether it is allowed to replace
-an ISO directory by a non-directory file.
-If a directory is copied to a directory, then both directory trees will
-be merged. So this switch applies only to situations where non-directories
-hit directories.
-
-The "Enforce disk dir write access" switch enables the options "auto_chmod_on"
-and "sort_lba_on". "auto_chmod_on" allows xorriso to give itself temporariy
-w-permission to all disk directories which are owned by the xorriso user.
-This is not without dangers, of course, but comes in handy with restoring of
-backups.
-Option "sort_lba_on" reduces head-moves of optical drives and thus can
-speed up extraction substantially. It is bound to "auto_chmod_on" because
-else it might get in trouble when restoring ISO directories which offer
-no w-permission.
-
-The "Refresh avail:" button triggers a time consuming exact prediction
-of the free space on the medium in the output drive. For this purpose,
-the size of an ISO session with the pending changes is computed.
-With image files rather than real optical drives, the free space of
-the hosting filesystem is displayed.
-
-The "Insert from disk:" button executes command -map with the disk file
-address that is given by the text field right to the button.
-
-The switch "Underneath" has the same effect as with file extraction:
-If enabled, a directory from disk will not be unpacked to its single files
-but put underneath the target address by its own leaf name.
-If the switch "Selected" is enabled, then the given disk file or tree will
-be inserted at or underneath the only selected item in the box inderneath
-"ISO directory:".
-
-The text field in the "ISO directory:" line displays the current ISO
-directory and can be used to toggle its path directly. Hitting the
-Return key causes the current directory to change and the display in
-the box underneath to be refreshed.
-
-The "Up" buttons move the current ISO directory one directory level up.
-
-The "Verify" button executes -md5_check_r "SORRY" with the current ISO
-directory. ISO images bear MD5s for each data file if they were produced
-by xorriso with -md5 "on" resp. -for_backup. This frontend enables this
-feature on startup.
-
-The list box underneath the "ISO directory:" line displays the files in
-the current ISO directory. One or more item can be selected and play a
-role with extraction or insertion of files.
-Most of the buttons underneath the box operate on the selected items
-unconditionally.
-
-The "Verify" button in the "ISO selection:" line executes command
--md5_check_r "SORRY" with each of the selected items.
-
-The "Delete" button executes command -rm_r with each of the selected items.
-
-The "Rename to:" button iuses command -mv to move each of the selected
-items to the address that is given by the text field right to the button.
-If this address points to an existing ISO directory, then the items will
-be moved underneath that directory and keep their leaf names.
-Else there may be only one selected item which will be renamed to the
-given address.
-
-The "Make dir" button executes command -mkdir with the address in the
-text field to its left (the same as used by "Rename to:"). Useful to
-create a target directory before moving the selection.
-
diff --git a/frontend/xorriso-tcltk b/frontend/xorriso-tcltk
index ee76ab0d..595a7960 100755
--- a/frontend/xorriso-tcltk
+++ b/frontend/xorriso-tcltk
@@ -39,6 +39,9 @@ proc print_usage {argv0} {
   puts stderr "     It is important that the parent of xorriso and of this"
   puts stderr "     tcl/tk frontend opens the named pipe for commands before"
   puts stderr "     it opens the named pipe for replies. This avoids deadlock."
+  puts stderr " --silent_start"
+  puts stderr "     Do not issue the start message xorriso-tcltk-version."
+  puts stderr "     This works only if --silent_start is the first argument."
   puts stderr " --geometry {+|-}X{+|-}Y"
   puts stderr "     Sets the position of the main window."
   puts stderr " --click_to_focus"
@@ -51,7 +54,12 @@ proc print_usage {argv0} {
   puts stderr "     Set a file address for logging of xorriso commands and"
   puts stderr "     reply messages. The log lines will be appended."
   puts stderr ""
-  puts stderr "Either --stdio or --named_pipes must be given for a program run."
+  puts stderr "If neither --stdio nor --named_pipes is given, then this script"
+  puts stderr "will try to locate itself in the filesystem and start a xorriso"
+  puts stderr "run that launches it again."
+  puts stderr ""
+  puts stderr "In the running GUI, click with the rightmost mouse button on"
+  puts stderr "any GUI element to get its particular help text."
   puts stderr ""
 }
 
@@ -716,6 +724,7 @@ proc setup_xorriso {} {
   set cmd "$cmd -hardlinks off"
 
   set cmd "$cmd -abort_on NEVER"
+  set cmd "$cmd -return_with ABORT 32"
   set cmd "$cmd -report_about UPDATE"
   set cmd "$cmd -osirrox on"
   set cmd "$cmd -iso_rr_pattern off"
@@ -1014,10 +1023,11 @@ set busy_text_exists 0
 # Whether to demand a click before focus goes to entry or listbox
 set click_to_focus "0"
 
-# Whether .ack_window resp. .yesno_window is already displayed 
+# Whether .ack_window , .yesno_window , .help_window is already displayed 
 # (>>> Better would be to block user interaction until they are gone)
 set ack_window_is_active 0
 set yesno_window_is_active 0
+set help_window_is_active 0
 
 
 # ------ GUI callback procedures ----
@@ -1207,6 +1217,7 @@ proc scan_for_drives {} {
   .drivelist delete 0 [expr "$max_idx-1"]
   set devlist ""
 
+  reset_highest_cmd_sev
   clear_sieve
   send_marked_cmd "-devices"
   set max_idx 0
@@ -2282,6 +2293,56 @@ proc window_ack {question button_color where} {
 }
 
 
+# Destroy the help pop-up window.
+#
+proc destroy_help {w} {
+  global help_window_is_active
+
+  if {"$w" != ""} {
+    destroy "$w"
+  }
+  set help_window_is_active 0
+}
+
+
+# Pop-up a window which shows a help text and a Close button.
+#
+proc window_help {about_what button_color} {
+  global help_window_is_active
+  global .help_window
+
+  set color "#F0F0F0"
+
+  set re_use_widgets 0
+  set w {.help_window}
+  if {"$help_window_is_active" == 0} {
+    toplevel $w -borderwidth 20 -class Help
+    wm title $w "xorriso-tcltk help text"
+    set help_window_is_active 1
+  } else {
+    set re_use_widgets 1
+  }
+  set helptext [tell_helptext "$about_what"] 
+  if {"$re_use_widgets" == 1} {
+    $w.text configure -state normal
+    $w.text delete 1.0 end
+    $w.text insert end "$helptext"
+    raise $w
+  } else {
+    # wm geometry $w +0+0
+    set destroy_cmd "destroy_help $w"
+
+    text $w.text -width 80 -height 20 -relief flat -borderwidth 0
+    $w.text insert end "$helptext"
+    button $w.close -text "Close" -command "$destroy_cmd" \
+                    -background "$button_color"
+    pack $w.text -side top -expand 1 -fill both
+    pack $w.close -side top 
+  }
+  $w.text configure -state disabled
+}
+
+
 # Display the busy/ready state of xorriso.
 # Called with 1 by sender of commands and with 0 by receivers of replies .
 #  
@@ -2390,30 +2451,38 @@ proc init_input {} {
                     -side top -anchor w -expand 1 -fill both
 
   button .end_button -text "End" -command "end_xorriso"
+  bind_help .end_button "End"
+
   if {[string length "$xorriso_version"] > 10} {
     set xorriso_version [string range "$xorriso_version" 0 9]
   }
   label .xorriso_version -text "xorriso-$xorriso_version"
+  bind_help .xorriso_version "version"
   frame .busy -relief ridge -borderwidth 2
   label .busy_text -width 5 -text "busy"
+  bind_help .busy_text "ready/busy"
   set busy_text_exists 1
   pack .busy_text -in .busy
 
   button .refresh_state -text "Refresh state display" \
                         -command "refresh_state"
+  bind_help .refresh_state "Refresh state display"
 
   checkbutton .log_pipes_switch -text "Log pipes" \
                                 -indicatoron 1 -selectcolor "" \
                                 -relief ridge -borderwidth 2 \
                                 -variable logging \
                                 -onvalue 1 -offvalue 0
+  bind_help .log_pipes_switch "Log pipes"
+  button .help -text "Help" -command {window_help "Help" "grey"}
+  bind_help .help "Help"
 
   init_cmdline
 
   pack .end_button .xorriso_version .busy -in .input_line1 -side left
   pack .cmdline \
        -in .input_line1 -side left -expand 1 -fill both
-  pack .refresh_state .log_pipes_switch -in .input_line1 -side left
+  pack .refresh_state .log_pipes_switch .help -in .input_line1 -side left
 }
 
 
@@ -2426,9 +2495,11 @@ proc init_cmdline {} {
   frame .cmdline -borderwidth 0
 
   label .cmdline_text -width 10 -text "Command:"
+  bind_help .cmdline_text "Command:"
   entry .cmdline_entry -width 60 -relief sunken -bd 1 \
                               -textvariable cmdline
   bind_entry_keys .cmdline_entry {cmdline_return}
+  bind_help .cmdline_entry "Command:"
 
   # >>> is there a chance to get a history on an entry ?
 
@@ -2451,6 +2522,7 @@ proc init_msgbox {} {
                    -yscrollcommand ".msgscroll set" \
                    -exportselection $export_msg_selection
   bind_listbox_keys ".msglist" "$msglist_lines" 
+  bind_help .msglist "message box"
   set msglist_running 1
   foreach i "$pre_msglist" {
 
@@ -2493,9 +2565,12 @@ proc init_cmd_errmsg {} {
   frame .cmd_errmsg -borderwidth "$borderwidth"
 
   label .cmd_errmsg_label -width 14 -text "Recent problem:"
-  entry .cmd_errmsg_msg -width 80 -relief raised -bd 1 \
-                      -textvariable highest_cmd_sev_msg
+  bind_help .cmd_errmsg_label "Recent problem:"
+  label .cmd_errmsg_msg -width 80 -relief ridge -bd 2 \
+                        -anchor w \
+                        -textvariable highest_cmd_sev_msg
   # (no keys, no focus)
+  bind_help .cmd_errmsg_msg "Recent problem:"
   pack .cmd_errmsg_label -in .cmd_errmsg -side left
   pack .cmd_errmsg_msg -in .cmd_errmsg -side left -expand 1 -fill both
 }
@@ -2511,12 +2586,16 @@ proc init_total_errmsg {} {
   frame .total_errmsg -borderwidth "$borderwidth"
 
   label .total_errmsg_label -text "Worst problem:" -width 14
+  bind_help .total_errmsg_label "Worst problem:"
   button .total_errmsg_clear -text "Clear" \
                              -width 5 \
                              -command "clear_total_errmsg"
-  entry .total_errmsg_msg -width 80 -relief raised -bd 1 \
-                      -textvariable highest_total_sev_msg
+  bind_help .total_errmsg_clear "Clear"
+  label .total_errmsg_msg -width 80 -relief ridge -bd 2 \
+                          -anchor w \
+                          -textvariable highest_total_sev_msg
   # (no keys, no focus)
+  bind_help .total_errmsg_msg "Worst problem:"
   pack .total_errmsg_label -in .total_errmsg -side left 
   pack .total_errmsg_msg -in .total_errmsg -side left -expand 1 -fill both
   pack .total_errmsg_clear -in .total_errmsg -side left
@@ -2540,6 +2619,7 @@ proc init_drivebox {} {
                      -yscrollcommand ".drivescroll set" \
                      -exportselection $export_selection
   bind_listbox_keys ".drivelist" "$drivelist_lines" 
+  bind_help .drivelist "drivelist"
   scrollbar .drivescroll -command ".drivelist yview"
 
   pack .drivelist   -in .drivelistbox -side left  -expand 1 -fill both
@@ -2548,17 +2628,24 @@ proc init_drivebox {} {
   frame .drive_picker -borderwidth $borderwidth
   button .drive_scan -text "Scan for drives" \
                      -command "scan_for_drives"
+  bind_help .drive_scan "Scan for drives"
   button .drive_pick_in -text "Pick input drive" \
                         -command "pick_indev"
+  bind_help .drive_pick_in "Pick input drive"
   button .drive_pick_out -text "Pick output drive" \
                          -command "pick_outdev"
+  bind_help .drive_pick_out "Pick output drive"
   button .drive_pick_both -text "Pick drive for both roles" \
                          -command "pick_dev"
+  bind_help .drive_pick_both "Pick drive for both roles"
   button .drive_drop_both -text "Give up drives" \
                          -command "give_up_dev"
+  bind_help .drive_drop_both "Give up drives"
   button .drive_calm -text "Calm drives" \
                          -command "calm_drives"
+  bind_help .drive_calm "Calm drives"
   button .iso_rollback_button -text "Rollback" -command {iso_rollback}
+  bind_help .iso_rollback_button "Rollback"
 
   pack .drive_scan \
        .drive_pick_in .drive_pick_out .drive_pick_both \
@@ -2601,11 +2688,15 @@ proc init_indev {} {
   frame .indev -borderwidth $borderwidth
 
   button .indev_eject -text "Eject" -command {eject_indev}
+  bind_help .indev_eject "Eject (indev)"
   label .indev_label -width 22 -text "Input drive or image  "
+  bind_help .indev_label "Input drive or image"
   entry .indev_entry -width 40 -relief sunken -bd 1 \
                      -textvariable indev_adr
   bind_entry_keys .indev_entry {indev_return}
+  bind_help .indev_entry  "Input drive or image"
   label .indev_summary -width 65 -text "" -relief ridge -borderwidth 2
+  bind_help .indev_summary  "input drive info"
   pack .indev_eject .indev_label .indev_entry .indev_summary \
        -in .indev -side left -expand 1 -fill both
 }
@@ -2620,11 +2711,15 @@ proc init_outdev {} {
   frame .outdev -borderwidth $borderwidth
 
   button .outdev_eject -text "Eject" -command {eject_outdev}
+  bind_help .outdev_eject "Eject (outdev)"
   label .outdev_label -width 22 -text "Output drive or image" 
+  bind_help .outdev_label "Output drive or image"
   entry .outdev_entry -width 40 -relief sunken -bd 1 \
                       -textvariable outdev_adr
   bind_entry_keys .outdev_entry {outdev_return}
+  bind_help .outdev_entry "Output drive or image"
   label .outdev_summary -width 65 -text "" -relief ridge -borderwidth 2
+  bind_help .outdev_summary "output drive info"
   pack .outdev_eject .outdev_label .outdev_entry .outdev_summary \
        -in .outdev -side left -expand 1 -fill both
 }
@@ -2643,30 +2738,38 @@ proc init_burn {} {
  
   button .burn_blank_button -text "Blank" \
                             -command {burn_blank}
+  bind_help .burn_blank_button "Blank"
   button .burn_format_button -text "Format" \
                              -command {burn_format}
+  bind_help .burn_format_button "Format"
   button .burn_commit_button -text "Write ISO session" \
                              -command {burn_commit}
+  bind_help .burn_commit_button "Write ISO session"
   button .burn_write_image -text "Burn image file:" \
                            -command {burn_write_image}
+  bind_help .burn_write_image "Burn image file:"
   entry .burn_write_image_entry -width 40 -relief sunken -bd 1 \
                                 -textvariable burn_write_image_adr
   bind_entry_keys .burn_write_image_entry {burn_write_image}
+  bind_help .burn_write_image_entry "Burn image file:"
   checkbutton .burn_write_close -text "Close" \
                                 -indicatoron 1 -selectcolor "" \
                                 -relief ridge -borderwidth 2 \
                                 -variable burn_write_close \
                                 -onvalue 1 -offvalue 0
+  bind_help .burn_write_close "Close"
   checkbutton .burn_write_tao -text "TAO" \
                                 -indicatoron 1 -selectcolor "" \
                                 -relief ridge -borderwidth 2 \
                                 -variable burn_write_tao \
                                 -onvalue 1 -offvalue 0
+  bind_help .burn_write_tao "TAO"
   checkbutton .burn_write_defect_mgt -text "Defect Mgt" \
                                 -indicatoron 1 -selectcolor "" \
                                 -relief ridge -borderwidth 2 \
                                 -variable burn_write_defect_mgt \
                                 -onvalue 1 -offvalue 0
+  bind_help .burn_write_defect_mgt "Defect Mgt"
   pack .burn_blank_button .burn_format_button \
        .burn_commit_button .burn_write_close .burn_write_tao \
        .burn_write_defect_mgt \
@@ -2687,12 +2790,17 @@ proc init_isobox {} {
 
   label .isodir_label -text "ISO directory:" \
                       -width 14
+  bind_help .isodir_label "ISO directory:"
   entry .isodir_entry -width 60 -relief sunken -bd 1 \
                       -textvariable isodir_adr
   bind_entry_keys .isodir_entry {isodir_return "isodir_entry"}
+  bind_help .isodir_entry "ISO directory:"
   button .isodir_verify -text "Verify" -command {isodir_verify}
+  bind_help .isodir_verify "Verify"
   button .isodir_up -text "Up" -command {isodir_up}
+  bind_help .isodir_up "Up"
   button .isodir_up2 -text "Up" -command {isodir_up}
+  bind_help .isodir_up2 "Up"
   pack .isodir_label .isodir_up \
        -in .isodir -side left
   pack .isodir_entry \
@@ -2705,6 +2813,7 @@ proc init_isobox {} {
                    -yscrollcommand ".isoscroll_y set" \
                    -xscrollcommand ".isoscroll_x set" \
                    -exportselection $export_selection
+  bind_help .isolist "isolist"
   bind_listbox_keys ".isolist" "$isolist_lines" 
   scrollbar .isoscroll_y -command ".isolist yview"
   scrollbar .isoscroll_x -orient horizontal -command ".isolist xview"
@@ -2731,19 +2840,25 @@ proc init_isomanip {} {
   frame .isomanip_move -borderwidth 0
  
   label .isomanip_prefix -text "ISO selection:"
+  bind_help .isomanip_prefix "ISO selection:"
 
   button .isomanip_verify_button -width 8 -text "Verify" \
                                 -command {isomanip_verify}
+  bind_help .isomanip_verify_button "Verify (selection)"
   button .isomanip_rm_r_button -width 8 -text "Delete" \
                                 -command {isomanip_rm_r}
+  bind_help .isomanip_rm_r_button "Delete"
   button .isomanip_move_button -text "Rename to:" \
                                -command {isomanip_mv}
+  bind_help .isomanip_move_button "Rename to:"
   button .isomanip_mkdir_button -width 8 -text "Make dir" \
                                 -command {isomanip_mkdir}
+  bind_help .isomanip_mkdir_button "Make dir"
   entry .isomanip_move_target -width 60 -relief sunken -bd 1 \
                              -textvariable isomanip_move_target
   # bind_entry_keys .isomanip_move_target {isomanip_mv}
   bind_entry_keys .isomanip_move_target ""
+  bind_help .isomanip_move_target "rename and mkdir target"
   pack .isomanip_prefix .isomanip_verify_button .isomanip_rm_r_button \
        .isomanip_move_button .isomanip_move_target .isomanip_mkdir_button \
        -in .isomanip_move -side left -expand 1 -fill both
@@ -2783,19 +2898,23 @@ proc init_extract {} {
   button .extract_button -text "Extract to disk:" \
                          -width 17 \
                          -command {extract_to}
+  bind_help .extract_button "Extract to disk:"
   entry .extract_entry -width 40 -relief sunken -bd 1 \
                        -textvariable "extract_to_adr"
   bind_entry_keys .extract_entry {extract_to}
+  bind_help .extract_entry "Extract to disk:"
   checkbutton .extract_underneath -text "Underneath" \
                                   -indicatoron 1 -selectcolor "" \
                                   -relief ridge -borderwidth 2 \
                                   -variable extract_underneath \
                                   -onvalue 1 -offvalue 0
+  bind_help .extract_underneath "Underneath (extract)"
   checkbutton .extract_from_selected -text "Selected" \
                                      -indicatoron 1 -selectcolor "" \
                                      -relief ridge -borderwidth 2 \
                                      -variable extract_from_selected \
                                      -onvalue 1 -offvalue 0
+  bind_help .extract_from_selected "Selected (extract)"
   pack .extract_button -in .extract_frame -side left
   pack .extract_entry \
        -in .extract_frame -side left -expand 1 -fill both
@@ -2818,23 +2937,28 @@ proc init_localfs_aux {} {
                                       -relief ridge -borderwidth 2 \
                                       -variable overwrite_files \
                                       -onvalue 1 -offvalue 0
+  bind_help .overwrite_files_button "Overwrite files"
   checkbutton .overwrite_dir_button -text "Overwrite ISO dirs" \
                                       -indicatoron 1 -selectcolor "" \
                                       -relief ridge -borderwidth 2 \
                                       -variable overwrite_dirs \
                                       -onvalue 1 -offvalue 0
+  bind_help .overwrite_dir_button "Overwrite ISO dirs"
   checkbutton .extract_auto_chmod   -text "Enforce disk dir write access" \
                                       -indicatoron 1 -selectcolor "" \
                                       -relief ridge -borderwidth 2 \
                                       -variable extract_auto_chmod \
                                       -onvalue 1 -offvalue 0
+  bind_help .extract_auto_chmod "Enforce disk dir write access"
   pack .overwrite_files_button .overwrite_dir_button .extract_auto_chmod \
        -in .localfs_aux_frame -side left
 
   button .avail_button -text "Refresh avail:" \
                              -command {refresh_avail}
+  bind_help .avail_button "Refresh avail:"
   frame .avail_label_frame -relief ridge -borderwidth 2
   label .avail_label -width 10 -text ""
+  bind_help .avail_label "Refresh avail:"
   pack .avail_label -in .avail_label_frame
 
   pack .avail_label_frame .avail_button -in .localfs_aux_frame -side right
@@ -2855,19 +2979,23 @@ proc init_insert {} {
   button .insert_button -text "Insert from disk:" \
                         -width 17 \
                         -command {insert_from}
+  bind_help .insert_button "Insert from disk:"
   entry .insert_entry -width 40 -relief sunken -bd 1 \
                       -textvariable "insert_from_adr"
   bind_entry_keys .insert_entry {insert_from}
+  bind_help .insert_entry "Insert from disk:"
   checkbutton .insert_underneath -text "Underneath" \
                                  -indicatoron 1 -selectcolor "" \
                                  -relief ridge -borderwidth 2 \
                                  -variable insert_underneath \
                                  -onvalue 1 -offvalue 0
+  bind_help .insert_underneath "Underneath (insert)"
   checkbutton .insert_at_selected -text "Selected" \
                                   -indicatoron 1 -selectcolor "" \
                                   -relief ridge -borderwidth 2 \
                                   -variable insert_at_selected \
                                   -onvalue 1 -offvalue 0
+  bind_help .insert_at_selected "Selected (insert)"
   pack .insert_button -in .insert_from_frame -side left
   pack .insert_entry \
        -in .insert_from_frame -side left -expand 1 -fill both
@@ -2937,6 +3065,550 @@ proc bind_entry_keys {entry return_cmd} {
 }
 
 
+# Bind a help text to a widget.
+#
+proc bind_help {to_what help_name} {
+  bind $to_what <Button-3> "window_help \"$help_name\" grey"
+}
+
+
+# The central storage for help texts.
+#
+proc tell_helptext {what} {
+  global own_version argv0
+
+  if {"$what" == "Help"} {
+    return \
+"For getting particular help texts:
+
+Click the rightmost mouse button on any button, list, or text field of the GUI. 
+
+-----------------------------------------------------------------------------
+
+xorriso-tcltk is mainly a proof of concept for a frontend that operates
+xorriso in dialog mode.
+
+It demonstrates some of xorriso's multi-session features with ISO 9660
+filesystems on optical media (CD, DVD, BD) or in disk files.
+
+Copyright (C) 2012, Thomas Schmitt <scdbackup@gmx.net>, libburnia-project.org
+Provided under GNU GPL version 2 or later.
+
+-----------------------------------------------------------------------------
+
+For a help text about startup options of this frontend, execute:
+
+  $argv0 --help"
+  }
+  if {"$what" == "End"} {
+    return \
+"The \"End\" button leads to the end of frontend and xorriso process."
+  }
+  if {"$what" == "version"} {
+    return \
+"The field between \"End\" button and ready/busy field displays the
+version of the serving xorriso program.
+
+xorriso is a program which copies file objects from POSIX compliant
+filesystems into Rock Ridge enhanced ISO 9660 filesystems and allows
+session-wise manipulation of such filesystems. It can load the management
+information of existing ISO images and it writes the session results to
+optical media or to filesystem objects.
+Vice versa xorriso is able to restore file objects from ISO 9660 filesystems.
+
+xorriso-tcltk-$own_version is mainly a proof of concept for a frontend
+that operates xorriso in dialog mode.
+
+It exercises several fundamental gestures of communication:
+- connecting via two pipes
+- sending commands
+- receiving replies
+- inquiring the xorriso message sieve
+- using the xorriso parsing service
+
+Note that any other language than Tcl/Tk could be used, if it only can
+do i/o via standard input and standard output or via named pipes.
+Further it has to perform integer arithmetics and string manipulations.
+And, well, a graphical widget set would be nice."
+  }
+  if {"$what" == "Refresh state display"} {
+    return \
+"The \"Refresh state display\" button causes several text fields and list
+boxes to update their display after manually transmitted commands may
+have changed the state of drives or ISO model."
+  }
+  if {"$what" == "ready/busy"} {
+    return \
+"The ready/busy field indicates whether a xorriso command is being executed
+and the frontend is still waiting for its reply messages."
+  }
+  if {"$what" == "Command:"} {
+    return \
+"The \"Command:\" field can be used to send commands to xorriso.
+See the manual page of xorriso for its concepts and commands."
+  }
+  if {"$what" == "Refresh state display"} {
+    return \
+"The \"Refresh state display\" button causes the other two main areas to update
+their display after manually transmitted commands may have changed the state
+of drives or ISO model."
+  }
+  if {"$what" == "Log pipes"} {
+    return \
+"The \"Log pipes\" switch controls whether all xorriso commands and replies
+shall be logged to standard error resp. to the file that has been given
+with program argument --log_file.
+
+Caution: This log is verbous."
+  }
+  if {"$what" == "message box"} {
+    return \
+"The message box displays commands sent to xorriso and messages received
+from xorriso.
+
+Many commands which are emitted by the GUI will hide themselves and their
+replies from this display. All event messages with severity WARNING or
+higher will show up, nevertheless."
+  }
+  if {"$what" == "Recent problem:"} {
+    return \
+"The \"Recent problem:\" field shows the most severe event message that occured
+during the execution of the most recent command. It also displays the most
+recent problem message from the frontend program itself.
+
+Several commands emitted by the GUI will not clear this display. But any
+manually transmitted command and the major GUI gestures will do.
+"
+  }
+  if {"$what" == "Worst problem:"} {
+    return \
+"The \"Worst problem:\" field shows the most severe event message that occured
+since last time the \"Clear\" button was hit. It will not clear automatically."
+  }
+  if {"$what" == "Clear"} {
+    return \
+"The \"Clear\" button removes the message from the \"Worst problem:\" field."
+  }
+  if {"$what" == "Scan for drives"} {
+    return \
+"The \"Scan for drives\" button executes command -devices and puts the list
+of found optical drives into the box underneath the button.
+
+Scanning should be done before any ISO image manipulations because xorriso
+has to give up its aquired drives in order to perform the scan run.
+
+To become visible and to be usable, the drives have to offer rw-permission
+to the user of this program. If drives do not show up, then consider to
+become superuser and to execute
+  xorriso -devices
+Then apply
+  chmod a+rw 
+to the listed device files. (Consider to use finer means of permission
+granting for a permanent solution.)"
+  }
+  if {"$what" == "Pick input drive"} {
+    return \
+"The \"Pick input drive\" button executes command -indev and obtains some
+information about the medium status. This info is displayed in the 
+\"Input drive or image\" line. 
+Further it causes the display of the ISO image model to be updated.
+
+The medium in the input drive must be blank or contain a valid ISO 9660
+filesystem.
+Choosing an input drive causes a root directory to be created in the ISO
+model of xorriso. If there is a valid ISO filesystem in the input drive
+then its directory tree gets loaded underneath that model root directory.
+
+The input drive may also be a data file on hard disk if that file contains
+an ISO 9660 filesystem image. See field \"Input drive or image\"."
+  }
+  if {"$what" == "Pick output drive"} {
+    return \
+"The \"Pick output drive\" button executes command -outdev and obtains some
+information about the medium status. This info is displayed in the 
+\"Output drive or image\" line.
+
+The output drive may be empty or loaded with a medium, that may be blank,
+appendable or closed.
+It is usable for writing only if there is a medium inserted which is either
+blank or appendable. Button \"Blank\" can bring appendable or closed media
+into blank state.
+
+The output drive may also be a data file on hard disk. See field
+\"Output drive or image\"."
+It is considered appendable if it contains an ISO 9660 filesystem image.
+It is considered blank if it is empty or marked as blank by button \"Blank\".
+It is considered closed if it contains other data."
+  }
+  if {"$what" == "Pick drive for both roles"} {
+    return \
+"The \"Pick drive for both roles\" button executes command -dev and obtains some
+information about the medium status. This info is displayed in the
+\"Input drive or image\" line and in the \"Output drive or image\" line.
+Further it causes the display of the ISO image model to be updated.
+
+The medium in the drive must be blank or contain a valid ISO 9660 filesystem.
+Else the drive will only be aquired as output drive.
+
+This drive configuration is the most usual one with xorriso. It loads
+an eventual ISO image, allows to manipulate it by insertion, deletion,
+and renaming. When this is done, the changes get written to the drive
+via button \"Write ISO session\".
+
+The drive may also be a data file on hard disk.
+See fields \"Input drive or image\" and \"Output drive or image\".
+It is considered appendable if it contains an ISO 9660 filesystem image.
+It is considered blank if it is empty or marked as blank by button \"Blank\".
+It is considered closed if it contains other data."
+  }
+  if {"$what" == "Give up drives"} {
+    return \
+"The \"Give up drives\" button executes commands -indev \"\" -outdev \"\"
+and clears both \"... drive or image\" lines, as well as the ISO model."
+  }
+  if {"$what" == "Calm drives"} {
+    return \
+"The \"Calm drives\" button executes command -calm_drives which tells the
+aquired optical drives to stop spinning until the next drive activity
+gets triggered."
+  }
+  if {"$what" == "Rollback"} {
+    return \
+"The \"Rollback\" button executes command -rollback which drops all pending
+changes of the ISO model and reloads it from the input drive, if one is
+aquired."
+  }
+  if {"$what" == "drivelist"} {
+    return \
+"The box underneath the \"Scan for drives\" button shows the optical drives
+which were found by the most recent scan run.
+
+A double-click on a drive item has the same effect as button
+\"Pick drive for both roles\".
+"
+  }
+  if {"$what" == "Input drive or image"} {
+    return \
+"The \"Input drive or image\" field displays the address of the input drive.
+Editing the drive address and pressing the Return key causes the execution
+of command -indev with the field content as drive address.
+
+Use this to load the model from an ISO image data file on hard disk.
+It is of course permissible that input image and output image are the
+same file.
+"
+  }
+  if {"$what" == "input drive info"} {
+    return \
+"The text field beneath the \"Input drive or image\" field displays the medium
+status of the input drive. It tells about the writability, the medium type,
+the number of ISO sessions, and the amount of readable data."
+  }
+  if {"$what" == "Eject (indev)"} {
+    return \
+"The \"Eject\" button beneath the \"Input drive or image\" field excutes
+command -eject \"in\"."
+  }
+  if {"$what" == "Output drive or image"} {
+    return \
+"The \"Output drive or image\" field displays the address of the output drive.
+Editing the drive address and pressing the Return key causes the execution
+of command -outdev with the field content as drive address.
+
+Use this to direct writing to an ISO image data file on hard disk.
+It is of course permissible that input image and output image are the
+same file.
+"
+  }
+  if {"$what" == "output drive info"} {
+    return \
+"The text beneath the \"Output drive or image\" field displays the medium
+status of the output drive. It tells about the writability, the medium type,
+the number of ISO sessions, and the amount of free space."
+  }
+  if {"$what" == "Eject (outdev)"} {
+    return \
+"The \"Eject\" button beneath the \"Output drive or image\" field excutes
+command -eject \"out\"."
+  }
+  if {"$what" == "Blank"} {
+    return \
+"The \"Blank\" button executes command -blank \"as_needed\" on the output drive.
+
+This also applies to ISO image data files and overwritable media like DVD+RW,
+which will get invalidated by a small write operation."
+  }
+  if {"$what" == "Format"} {
+    return \
+"The \"Format\" button executes -format \"as_needed\".
+
+This only applies to real optical drives and is of interest only with DVD-RW
+or BD-R media, which both can be used formatted and unformatted. Other media
+types which mandatorily need formatting will be formatted by the write
+commands.
+
+Formatted DVD-RW media have the advantage of being overwritable and thus
+being quickly blankable while maintaining the capability for multi-session.
+
+Formatted BD-R can perform Defect Management, which is of questionable value."
+  }
+  if {"$what" == "Write ISO session"} {
+    return \
+"The \"Write ISO session\" executes command -commit, which writes a session
+with all pending changes to the output drive.
+
+The output drive must be either blank or it must be the same as the input
+drive.
+
+Writing the session is the last step in the course of creating a new ISO
+filesystem or an add-on session that expands or changes the ISO filesystem
+on the medium of the output drive.
+So first choose a drive, then insert files from hard disk or do other
+manipulations, and then click \"Write ISO session\" to let xorriso
+write the data to medium or ISO image file.
+"
+  }
+  if {"$what" == "Close"} {
+    return \
+"The \"Close\" switch controls whether command -close \"on\" is emitted with
+\"Write ISO session\" or whether -as cdrecord option -multi is omitted with
+\"Burn image file:\".
+
+Closed optical media cannot be written any more unless they get blanked,
+which is not possible with CD-R, DVD-R, DVD+R, and BD-R.
+"
+  }
+  if {"$what" == "TAO"} {
+    return \
+"The \"TAO\" switch controls whether an incremental MMC write type shall be
+enforced with write commands.
+
+Normally xorriso will decide by medium status and job parameters which
+MMC write type to choose. Some drives at the edge of failure might work
+with the one write type while already failing with the other."
+  }
+  if {"$what" == "Defect Mgt"} {
+    return \
+"The \"Defect Mgt\" switch controls whether slow and error-prone drive internal
+check-reading shall be enabled when writing to formatted BD-R or BD-RE.
+"
+  }
+  if {"$what" == "Burn image file:"} {
+    return \
+"The \"Burn image file:\" button executes command -as \"cdrecord\" to
+burn a data file from hard disk onto the output drive.
+The address of the disk file is taken from the neighboring text field.
+
+The medium in the drive may be blank or appendable."
+  }
+  if {"$what" == "Extract to disk:"} {
+    return \
+"The \"Extract to disk:\" button executes command -extract with the whole
+tree of the current ISO directory or with the selected items of the box
+underneath \"ISO directory:\".
+
+This copies the selected files or directory trees from the input drive
+to the address on hard disk which is given by the text field right of
+the button."
+  }
+  if {"$what" == "Underneath (extract)"} {
+    return \
+"The \"Underneath\" switch controls the effective hard disk target address
+of an item if the address in the \"Extract to disk:\" field points to a
+directory.
+
+If \"Underneath\" is enabled, then the file object from the ISO filesystem
+will be copied to its name underneath the hard disk directory.
+If \"Underneath\" is disabled then an ISO directory tree item will be merged
+with the disk directory tree at the given address.
+
+Example:
+Selected are \"/iso_dir\" and \"/iso_file\".
+Address for hard disk is \"/tmp/from_iso\". Switch \"Selected\" is enabled.
+\"Underneath\" enabled causes commands:
+  -extract /iso_dir /tmp/from_iso/iso_dir
+  -extract /iso_file /tmp/from_iso/iso_file
+\"Underneath\" disabled:
+  -extract /iso_dir /tmp/from_iso
+  -extract /iso_file /tmp/from_iso
+The last command will fail because /tmp/from_iso already exists as directory."
+  }
+  if {"$what" == "Selected (extract)"} {
+    return \
+"The \"Selected\" switch controls whether the whole current ISO directory,
+or only the selected items shall be copied to hard disk.
+"
+  }
+  if {"$what" == "Overwrite files"} {
+    return \
+"The \"Overwrite files\" switch controls whether existing files may be
+overwritten in the ISO image or by extraction on hard disk.
+
+The frontend program will only detect the most obvious name collisions,
+but xorriso will reliably refuse to overwrite files if this is banned."
+  }
+  if {"$what" == "Overwrite ISO dirs"} {
+    return \
+"The \"Overwrite ISO dirs\" switch controls whether it is allowed to replace
+an ISO directory by a non-directory file.
+
+If a directory is copied to a directory, then both directory trees will
+be merged. So this switch applies only to situations where non-directories
+hit directories."
+  }
+  if {"$what" == "Enforce disk dir write access"} {
+    return \
+"The \"Enforce disk dir write access\" switch enables the options -osirrox
+\"auto_chmod_on\" and \"sort_lba_on\" which influence file extraction.
+
+\"auto_chmod_on\" allows xorriso to give itself temporariy w-permission to
+all disk directories which are owned by the xorriso user. This is not
+without dangers, of course, but comes in handy with restoring of backups.
+
+Option \"sort_lba_on\" reduces head-moves of optical drives and thus can
+speed up extraction substantially. It is bound to \"auto_chmod_on\" because
+else it might get in trouble when restoring ISO directories which offer
+no w-permission."
+  }
+  if {"$what" == "Refresh avail:"} {
+    return \
+"The \"Refresh avail:\" button triggers a time consuming exact prediction
+of the free space on the medium in the output drive. For this purpose,
+the size of an ISO session with the pending changes is computed.
+With image files rather than real optical drives, the free space of
+the hosting filesystem is displayed."
+  }
+  if {"$what" == "Insert from disk:"} {
+    return \
+"The \"Insert from disk:\" button executes command -map with the disk file
+address that is given by the text field right to the button.
+
+This inserts files or directory trees into the ISO image model and
+schedules them for being copied with the next \"Write ISO session\" run.
+
+The switches \"Underneath\" and \"Selected\" control what ISO address
+the inserted files shall have. You may use buttons \"Delete\" and
+\"Rename to:\" for further adjustments.
+"
+  }
+  if {"$what" == "Underneath (insert)"} {
+    return \
+"The \"Underneath\" switch controls the effective ISO target address
+if the address in the \"Insert from disk:\" field points to a hard disk
+directory.
+
+If \"Underneath\" is enabled, a directory from disk will not be unpacked
+to its single files but be put underneath the target address by its own
+leaf name."
+
+If \"Underneath\" is disabled then the directory itself will not show up in
+the ISO image but only its files and sub directories will do."
+  }
+  if {"$what" == "Selected (insert)"} {
+    return \
+"If the switch \"Selected\" is enabled, then the given disk file or tree will
+be inserted at or underneath the only selected item in the box underneath
+\"ISO directory:\"."
+  }
+  if {"$what" == "ISO directory:"} {
+    return \
+"The current ISO directory shall be used to navigate in the ISO image model
+of xorriso. By default it is the target of file insertions and the source
+of file extractions.
+
+The text field in the \"ISO directory:\" line displays the current ISO
+directory and can be used to toggle its path directly.
+Hitting the Return key causes the current directory to change and the
+display in the box underneath to be refreshed.
+
+It is possible to choose the ISO directory by double-clicking an item
+in the box underneath the \"ISO directory:\" line.
+"
+  }
+  if {"$what" == "Up"} {
+    return \
+"The \"Up\" buttons move the current ISO directory one directory level up."
+  }
+  if {"$what" == "Verify"} {
+    return \
+"The \"Verify\" button executes -md5_check_r \"SORRY\" with the current ISO
+directory.
+
+This reads the content of all data files which are underneath the current ISO
+directory and which have MD5 checksums in the ISO image. 
+ISO images bear MD5 checksums for each data file if they were produced
+by xorriso with -md5 \"on\" resp. -for_backup. This frontend enables
+this feature on startup."
+  }
+  if {"$what" == "isolist"} {
+    return \
+"The list box underneath the \"ISO directory:\" line displays the files in
+the current ISO directory. One or more item can be selected and play a
+role with extraction or insertion of files.
+
+Most of the buttons underneath the box operate on the selected items
+unconditionally."
+  }
+  if {"$what" == "ISO selection:"} {
+    return \
+"The ISO selection consists of the items which are selected in the list box
+above the \"ISO selection:\" line.
+
+If the respective \"Selected\" switches are enabled, then the ISO selection
+is source of file extraction and target of file insertion.
+
+In any case it is the old nome of the \"Rename to:\" button, the victim
+of the \"Delete\" button, and the subject of the \"Verify\" button."
+  }
+  if {"$what" == "Verify (selection)"} {
+    return \
+"The \"Verify\" button in the \"ISO selection:\" line executes command
+-md5_check_r \"SORRY\" with each of the selected items.
+
+This reads the content of all data files which are selected or underneath
+selected directories and which have MD5 checksums in the ISO image. 
+ISO images bear MD5 checksums for each data file if they were produced
+by xorriso with -md5 \"on\" resp. -for_backup. This frontend enables
+this feature on startup."
+  }
+  if {"$what" == "Delete"} {
+    return \
+"The \"Delete\" button executes command -rm_r with each of the selected items.
+
+This removes the affected files and directory trees from the ISO model.
+They will not show up in the directory tree of the next session that
+is written via \"Write ISO session\". Nevertheless they will stay present
+in earlier sessions if they were not freshly inserted after loading the
+ISO model from the input drive.
+"
+  }
+  if {"$what" == "Rename to:"} {
+    return \
+"The \"Rename to:\" button uses command -mv to move each of the selected
+items to the address that is given by the text field right to the button.
+
+If this address points to an existing ISO directory, then the items will
+be moved underneath that directory and keep their leaf names.
+Else there may be only one selected item which will be renamed to the
+given address."
+  }
+  if {"$what" == "Make dir"} {
+    return \
+"The \"Make dir\" button executes command -mkdir with the address in the
+text field to its left (the same as used by \"Rename to:\").
+
+Useful to create a target directory before moving the selection."
+  }
+  if {"$what" == "rename and mkdir target"} { 
+    return \
+"The text field between the \"Rename to:\" button and the \"Make dir\" button
+serves both buttons by providing the target address for renaming
+resp. directory creation."
+  }
+  return "--- No help text found for topic '$what'"
+}
+
+
 # ------- Misc helper procedures -------
 
 
@@ -3116,6 +3788,65 @@ proc central_exit {value} {
   exit $value
 }
 
+
+# Start a xorriso process which will in return launch another frontend
+# process. This is necessary until i learned how to create a pair of pipes
+# and to fork in Tcl.
+#
+proc start_xorriso {} {
+  global argv0 argv
+
+  set self ""
+  if {[string first "/" "$argv0"] != -1} {
+    set self "$argv0"
+  }
+  if {"$self" == ""} {
+    set self "/usr/bin/xorriso-tcltk"
+    if {[file executable "$self"] == 0} {set self ""}
+  }
+  if {"$self" == ""} {
+    set self "/usr/local/bin/xorriso-tcltk"
+    if {[file executable "$self"] == 0} {set self ""}
+  }
+  if {"$self" == ""} {
+    catch {
+      set conn [open "|which xorriso-tcltk" r]
+      set self [gets $conn]
+      close $conn
+    }
+  }
+  if {"$self" == ""} {
+    catch {
+      set conn [open "|sh -c \"type -p xorriso-tcltk\"" r]
+      set self [gets $conn]
+      close $conn
+    }
+  }
+  if {"$self" == ""} {
+    puts stderr "$argv0 :\n  Cannot locate address of script xorriso-tcltk in filesystem.\n"
+    puts stderr "You will have to use --stdio or --named_pipes."
+    puts stderr "See $argv0 --help\n"
+    central_exit 1
+  }
+
+  # eval is used to split $argv into single words
+  eval exec xorriso -launch_frontend "\"$self\"" --silent_start --stdio $argv -- 2>@stderr
+
+  central_exit 0
+}
+
+
+# Print a startup message to stderr if not the first argument is --silent_start
+#
+proc yell_xorriso_tcltk {} {
+  global argv own_version
+
+  if {[llength "$argv"] > 0} {
+    if {[lindex "$argv" 0] == "--silent_start"} {return ""}
+  }
+  puts stderr "xorriso-tcltk $own_version : Proof of concept for GUI frontends of xorriso\n"
+}
+
  
 # -------- start living
 
@@ -3140,6 +3871,9 @@ proc setup_by_args {argv0 argv} {
       print_usage "$argv0"
       central_exit 0
     }
+    if {"$opt" == "--silent_start"} {
+      set ok "1"
+    }
     if {"$opt" == "--stdio"} {
       set ok "1"
       set connection_defined 1
@@ -3161,6 +3895,7 @@ proc setup_by_args {argv0 argv} {
       # Just in case -geometry does not get eaten by wish
       incr i
       set main_window_geometry [lrange "$argv" "$i" "$i"]
+      set give_geometry [lrange "$argv" "$i" "$i"]
     }
     if {"$opt" == "--click_to_focus"} {
       set ok "1"
@@ -3194,9 +3929,7 @@ proc setup_by_args {argv0 argv} {
   }
 
   if {"$connection_defined" == 0} {
-    puts stderr "$argv0 : Either --stdio or --named_pipes must be given for a program run.\n"
-    print_usage "$argv0"
-    central_exit 1
+    start_xorriso
   }
 
   if {"$cmd_pipe_adr" == "" || "$reply_pipe_adr" == "" ||
@@ -3209,8 +3942,7 @@ proc setup_by_args {argv0 argv} {
   }
 }
 
-
-puts stderr "xorriso-tcltk $own_version : Proof of concept for GUI frontends\n"
+yell_xorriso_tcltk
 
 setup_by_args "$argv0" "$argv"
 check_xorriso_version