The WordPress source, licenced under the GNU General Public License version 2 (or later), resides in a Subversion repository at core.svn.wordpress.org.
WordPress also includes one binary file as part of the SWFUpload 2.2.0 package and licensed under the MIT license. The source can be downloaded here.
The wp-admin/js/revisions-js.php file is available in human-readable form here.
The uncompressed source for jQuery can be found at jQuery.com and is also available here.
The uncompressed source for TinyMCE can be found at tinymce.moxiecode.com and is also available here.
The uncompressed source for wp-includes/js/jquery/jquery.schedule.js is available here.
The uncompressed source for jQuery UI can be found at jqueryui.com and is also available here.
