Superez Wave Editor Pro
The edit-on Pro editor is a commercial product and not free/open source.
More Info 
Developer: ftp.drupal.org
License: Artistic License, GNU General Public License (GPL)
Operating System: Windows, Linux, Mac OS, BSD, Solaris
Kode Fu Pro is a VB Script editor which provides a user with very powerful auto complete (intellisense) options including user extendable auto complete.
Developer: Kodefupro
License: Freeware
Operating System: Windows
edit-on Pro is a cross-platform, in-browser, WYSIWYG editor Java applet which enables XHTML content authoring with XML markup.
Developer: RealObjects GmbH
License: Freeware
Operating System: All
HateML Pro is freeware product and a powerful PHP IDE with support for XHTML and CSS for both professional and novice users alike.
Developer: migajek.bravehost.com
License: Freeware
Operating System: All
Bluefish is a programmer's HTML editor written using GTK, designed to save the experienced webmaster some keystrokes.
Developer: Olivier Sessink
License: GNU General Public License (GPL)
Operating System: POSIX compatible operating systems including Linux, FreeBSD, MacOS-X, OpenBSD, Solaris and Tru64.
cssed is a small developer editor and validator, that tries to ease the CSS editing.
Developer: Iago Rubio
License: GNU General Public License (GPL)
Operating System: All 32-bit MS Windows (95/98/NT/2000/XP), All BSD Platforms (FreeBSD/NetBSD/OpenBSD/Apple Mac OS X), All POSIX (Linux/BSD/UNIX-like OSes)
Easy Personal Site Editor (EPSEditor) is a php-based online Content Management System (CMS) dedicated to personal website development.
Developer: Steven
License: GNU General Public License (GPL)
Operating System: Unix, Linux
KGuitar is powerful KDE-based music tabulature editor with support of guitar, drums, classic note scores, MIDI synthesizer output, chord, scales, modes, melody and rhythm construction and analysis tools, lots of tab effects, Guitar Pro files import.
Developer: kguitar
License: GNU General Public License (GPL)
Operating System: All POSIX (Linux/BSD/UNIX-like OSes)
Kwave is a sound editor for the KDE environment.
Developer: kwave
License: GNU General Public License (GPL)
Operating System: All POSIX (Linux/BSD/UNIX-like OSes), Linux
Blueshoes Spreadsheet Editor is a multi-platform compatible excel-like application.
Developer: BlueShoes
License: Freeware
Operating System: All
Blueshoes Wysiwyg Editor is a multi-platform compatible script that can be used as toolbar or editor box.
Developer: blueshoes.org
License: Freeware
Operating System: All
Powerful Web Based WYSIWYG HTML Editor that enhances profitability and productivity in your organization by allowing all employees to author web content without knowing HTML.
Developer: ezCore
License: Freeware
Operating System: Cross Platform
Boxer Text Editor is Windows compatible.
Developer: http://www.boxersoftware...
License: Freeware
Operating System: Windows
DzSoft Perl Editor is a tool for writing, editing, and debugging Perl/CGI scripts.
Developer: dzsoft.com
License: Freeware
Operating System: All
TeamCal Pro is a web application supporting project teams in scheduling their members' presence/absence.
Developer: George Lewe
License: Freeware
Operating System: PHP MySQL
HTMLArea is a free, customizable online editor.
Developer: dynarch.com
License: Freeware
Operating System: All
Softerra Hex Editor is a freeware component implemented as a 32-bit ActiveX (OCX) control, which will seamlessly integrate a hex editor in your applications.
Developer: download.softerra.com
License: Freeware
Operating System: All
HTML Application Editor allows you to create scripts on any operating systems.
Developer: SourceForge.net
License: Freeware
Operating System: All
PadPaper Editor is a simple text editor.
Developer: SourceForge.net
License: Freeware
Operating System: All
LIU Image Editor is a general image processing tool.
Developer: thejmaker.com
License: Freeware
Operating System: All