diff --git a/Makefile.am b/Makefile.am
index 37925fd..2e65e4d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -15,6 +15,7 @@ src_libisofs_la_SOURCES = \
 	src/error.h \
 	src/node.h \
 	src/node.c \
+	src/tree.c \
 	src/image.h \
 	src/image.c \
 	src/fsource.h \
diff --git a/TODO b/TODO
index 502d6cd..76680fb 100644
--- a/TODO
+++ b/TODO
@@ -11,6 +11,7 @@ TODO
 #00004 (fsource-h) -> Add a get_mime_type() function.
 #00005 (node.c) -> optimize iso_dir_iter_take. 
 #00006 (libisofs.h) -> define more replace values when adding a node to a dir
+#00007 (libisofs.h) -> expose iso_tree_add_new_file
 
 FIXME
 =====
diff --git a/src/libisofs.h b/src/libisofs.h
index 40d3fc5..ff9647e 100644
--- a/src/libisofs.h
+++ b/src/libisofs.h
@@ -428,6 +428,73 @@ int iso_dir_iter_take(IsoDirIter *iter);
  */
 int iso_dir_iter_remove(IsoDirIter *iter);
 
+/**
+ * Get the destination of a node (in UTF-8).
+ * The returned string belongs to the node and should not be modified nor
+ * freed. Use strdup if you really need your own copy.
+ */
+const char *iso_symlink_get_dest(const IsoSymlink *link);
+
+/**
+ * Set the destination of a link.
+ */
+void iso_symlink_set_dest(IsoSymlink *link, const char *dest);
+
+/**
+ * Add a new directory to the iso tree. Permissions, owner and hidden atts
+ * are taken from parent, you can modify them later.
+ * 
+ * @param parent 
+ *      the dir where the new directory will be created
+ * @param name
+ *      name for the new dir. If a node with same name already exists on
+ *      parent, this functions fails with ISO_NODE_NAME_NOT_UNIQUE.
+ * @param dir
+ *      place where to store a pointer to the newly created dir. No extra
+ *      ref is addded, so you will need to call iso_node_ref() if you really
+ *      need it. You can pass NULL in this parameter if you don't need the
+ *      pointer.
+ * @return
+ *     number of nodes in parent if success, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if parent or name are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ *         ISO_MEM_ERROR
+ */
+int iso_tree_add_new_dir(IsoDir *parent, const char *name, IsoDir **dir);
+
+/*
+TODO #00007 expose Strem and thi function:
+int iso_tree_add_new_file(IsoDir *parent, const char *name, stream, file)
+*/
+
+/**
+ * Add a new symlink to the directory tree. Permissions are set to 0777, 
+ * owner and hidden atts are taken from parent. You can modify any of them 
+ * later.
+ *  
+ * @param parent 
+ *      the dir where the new symlink will be created
+ * @param name
+ *      name for the new dir. If a node with same name already exists on
+ *      parent, this functions fails with ISO_NODE_NAME_NOT_UNIQUE.
+ * @param dest
+ *      destination of the link
+ * @param link
+ *      place where to store a pointer to the newly created link. No extra
+ *      ref is addded, so you will need to call iso_node_ref() if you really
+ *      need it. You can pass NULL in this parameter if you don't need the
+ *      pointer
+ * @return
+ *     number of nodes in parent if success, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if parent, name or dest are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ *         ISO_MEM_ERROR
+ */
+int iso_tree_add_new_symlink(IsoDir *parent, const char *name, 
+                             const char *dest, IsoSymlink **link);
+
 #define ISO_MSGS_MESSAGE_LEN 4096
 
 /** 
diff --git a/src/node.c b/src/node.c
index 9a4d53d..6f4eb2e 100644
--- a/src/node.c
+++ b/src/node.c
@@ -419,6 +419,25 @@ int iso_dir_iter_remove(IsoDirIter *iter)
     return iso_node_remove(pos);
 }
 
+/**
+ * Get the destination of a node (in UTF-8).
+ * The returned string belongs to the node and should not be modified nor
+ * freed. Use strdup if you really need your own copy.
+ */
+const char *iso_symlink_get_dest(const IsoSymlink *link)
+{
+    return link->dest;
+}
+
+/**
+ * Set the destination of a link.
+ */
+void iso_symlink_set_dest(IsoSymlink *link, const char *dest)
+{
+    free(link->dest);
+    link->dest = strdup(dest);
+}
+
 int iso_node_new_root(IsoDir **root)
 {
     IsoDir *dir;
diff --git a/src/tree.c b/src/tree.c
new file mode 100644
index 0000000..426e074
--- /dev/null
+++ b/src/tree.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2007 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+/*
+ * Functions that act on the iso tree.
+ */
+
+#include "libisofs.h"
+#include "node.h"
+#include "error.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+/**
+ * Add a new directory to the iso tree.
+ * 
+ * @param parent 
+ *      the dir where the new directory will be created
+ * @param name
+ *      name for the new dir. If a node with same name already exists on
+ *      parent, this functions fails with ISO_NODE_NAME_NOT_UNIQUE.
+ * @param dir
+ *      place where to store a pointer to the newly created dir. No extra
+ *      ref is addded, so you will need to call iso_node_ref() if you really
+ *      need it. You can pass NULL in this parameter if you don't need the
+ *      pointer.
+ * @return
+ *     number of nodes in dir if succes, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if parent or name are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ */
+int iso_tree_add_new_dir(IsoDir *parent, const char *name, IsoDir **dir)
+{
+    IsoDir *node;
+    IsoNode **pos;
+    time_t now;
+    
+    if (parent == NULL || name == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    
+    /* find place where to insert */
+    pos = &(parent->children);
+    while (*pos != NULL && strcmp((*pos)->name, name) < 0) {
+        pos = &((*pos)->next);
+    }
+    if (*pos != NULL && !strcmp((*pos)->name, name)) {
+        /* a node with same name already exists */
+        return ISO_NODE_NAME_NOT_UNIQUE;
+    }
+    
+    node = calloc(1, sizeof(IsoDir));
+    if (node == NULL) {
+        return ISO_MEM_ERROR;
+    }
+    
+    node->node.refcount = 1;
+    node->node.type = LIBISO_DIR;
+    node->node.name = strdup(name);
+    if (node->node.name == NULL) {
+        free(node);
+        return ISO_MEM_ERROR;
+    }
+    
+    /* permissions from parent */
+    node->node.mode = parent->node.mode;
+    node->node.uid = parent->node.uid;
+    node->node.gid = parent->node.gid;
+    node->node.hidden = parent->node.hidden;
+    
+    /* current time */
+    now = time(NULL);
+    node->node.atime = now;
+    node->node.ctime = now;
+    node->node.mtime = now;
+    
+    /* add to dir */
+    node->node.parent = parent;
+    node->node.next = (*pos)->next;
+    *pos = (IsoNode*)node;
+    
+    if (dir) {
+        *dir = node;
+    }
+    return ISO_SUCCESS;
+}
+
+/**
+ * Add a new symlink to the directory tree. Permissions are set to 0777, 
+ * owner and hidden atts are taken from parent. You can modify any of them 
+ * later.
+ *  
+ * @param parent 
+ *      the dir where the new symlink will be created
+ * @param name
+ *      name for the new dir. If a node with same name already exists on
+ *      parent, this functions fails with ISO_NODE_NAME_NOT_UNIQUE.
+ * @param dest
+ *      destination of the link
+ * @param link
+ *      place where to store a pointer to the newly created link. No extra
+ *      ref is addded, so you will need to call iso_node_ref() if you really
+ *      need it. You can pass NULL in this parameter if you don't need the
+ *      pointer
+ * @return
+ *     number of nodes in parent if success, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if parent, name or dest are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ *         ISO_MEM_ERROR
+ */
+int iso_tree_add_new_symlink(IsoDir *parent, const char *name, 
+                             const char *dest, IsoSymlink **link)
+{
+    IsoSymlink *node;
+    IsoNode **pos;
+    time_t now;
+    
+    if (parent == NULL || name == NULL || dest == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    
+    /* find place where to insert */
+    pos = &(parent->children);
+    while (*pos != NULL && strcmp((*pos)->name, name) < 0) {
+        pos = &((*pos)->next);
+    }
+    if (*pos != NULL && !strcmp((*pos)->name, name)) {
+        /* a node with same name already exists */
+        return ISO_NODE_NAME_NOT_UNIQUE;
+    }
+    
+    node = calloc(1, sizeof(IsoSymlink));
+    if (node == NULL) {
+        return ISO_MEM_ERROR;
+    }
+    
+    node->node.refcount = 1;
+    node->node.type = LIBISO_SYMLINK;
+    node->node.name = strdup(name);
+    if (node->node.name == NULL) {
+        free(node);
+        return ISO_MEM_ERROR;
+    }
+    
+    node->dest = strdup(dest);
+    if (node->dest == NULL) {
+        free(node->node.name);
+        free(node);
+        return ISO_MEM_ERROR;
+    }
+    
+    /* permissions from parent */
+    node->node.mode = S_IFLNK | 0777;
+    node->node.uid = parent->node.uid;
+    node->node.gid = parent->node.gid;
+    node->node.hidden = parent->node.hidden;
+    
+    /* current time */
+    now = time(NULL);
+    node->node.atime = now;
+    node->node.ctime = now;
+    node->node.mtime = now;
+    
+    /* add to dir */
+    node->node.parent = parent;
+    node->node.next = (*pos)->next;
+    *pos = (IsoNode*)node;
+    
+    if (link) {
+        *link = node;
+    }
+    return ISO_SUCCESS;
+}