QMWEdit (Qt Multi Window Editor)
A simple editor (IDE) for small C/C++ projects. The editor is based on Qt libraries 2.2.x . The goal of the project is to have an easy to use editor which provides a lot of nice features.
http://qmwedit.sourceforge.net/

JE, Just an Editor
Ordinary ASCII editor written entirely in Java. Though it is incomplete yet, it has already features you won't find easily in another editor. In general, it is a multi-file ASCII editor with syntax highlighting, which provides a graphical user interface. [GPL]
http://mathsrv.ku-eichstaett.de/MGF/homes/grothmann/je/

BVI - Binary Visual editor
Bvi stands for Binary VIsual editor. Bvi is a display oriented editor for binary files. Its command set is based on those of the vi texteditor.
http://bvi.sourceforge.net/

BVI - Binary Visual editor
Bvi stands for Binary VIsual editor. Bvi is a display oriented editor for binary files. Its command set is based on those of the vi texteditor.
http://bvi.sourceforge.net/

Stone's WebWriter
Danish award winning HTML editor for Windows
http://www.webwriter.dk/english/

Stone's WebWriter 3
Danish award winning HTML editor for Windows
http://www.webwriter.dk/english/

UltraEdit
Home of UltraEdit - the world's best text editor, hex editor, PHP editor, HTML editor, programmers editor from IDM Computer Solutions, Inc.
http://www.idmcomp.com/

Reactor Simulation Editor, Introduction with Examples
The Reactor Simulation Editor (rsedit) is a software package designed to solve finite difference equations in a simplified way. The tool kit includes: a geometry editor, data structure editors, equation editor and an HTML output library.
http://www.cas.mcmaster.ca/~gilbert/rse_intro/

The Hessling Editor (THE)
Editor based on the VM/CMS editor XEDIT, using REXX as its macro language. Available for UNIX (including Linux) as text and X11 variants, OS/2, Windows, BeOS, QNX and Amiga.
http://hessling-editor.sourceforge.net/

Rich Editor, cross-browser html editor
Rich Editor (RE) is a cross-browser and cross-platform WYSIWYG online html editor. Works in MSIE5.0+ for Windows and Netscape7.1/Mozilla1.4+. Can be used in CMSs or just instead of TEXTAREA tags. Implemented as a PHP and ASP class. Multiple instances support. XHTML 1.0 support. Advanced work with images, including file uploading, tables, links, stylesheets, FLASH, multilingual support and more! Security settings API.
http://www.richarea.com