AEditor
   A programmer's editor, written entirely in Ruby and thus easy to extend with Ruby customizations. Summary of the features, developers weblog, information about the development and download and installation instructions.
   http://aeditor.rubyforge.org/

Anyedit
   A development environment and Editor with a wide range of functionalities. Written entirely in C++.
   http://www.anyedit.org/

BVI - Binary Visual editor
   The bvi editor is a display-oriented editor for binary files, based on the vi text editor.
   http://bvi.sourceforge.net/

Bluefish
   A programmer's HTML editor written using GTK, designed to save the experienced webmaster some keystrokes. (C) [GNU/Linux, Unix]
   http://bluefish.openoffice.nl/

Code Browser
   A folding text editor that allows to structure source code using folders. [Win32/Linux]
   http://code-browser.sourceforge.net/

Cssed
   CSS editor featuring auto completion, syntax highlighting and syntax validation. (C, C++) [Linux]
   http://cssed.sourceforge.net

Ed!'s home on the web
   Ed! is a free open source text editor for the Linux platform. The source code is available for download. The site also provides some information on how to develop an editor in the Linux console environment using the ncurses library.
   http://www.geocities.com/edeater2001/

Eddi
   Tcl and tix based editor.
   http://eddi.sourceforge.net/

FTE Text Editor
   A folding text editor for programmers.
   http://fte.sourceforge.net/

Freddy
   An ascii text editor, primarily for programmers.
   http://freddy.sourceforge.net/

GNU Nano
   Clone of the Pico text editor with some enhancements. Available for Linux and DOS.
   http://www.nano-editor.org/

GNU TeXmacs
   Editor for extensible, structured and WYSIWYG technical documents, which was both inspired by TeX and GNU Emacs. The site provides documentation, source and binary packages, a feedback section and additional links.
   http://www.texmacs.org/

Gnotepad+
   An HTML/text editor using GTK+ and/or GNOME.
   http://gnotepad.sourceforge.net/

Helene
   A webbased syntax highlighting text editor (Javascript) [OS Independent].
   http://helene.muze.nl/

HexEdit
   A Macintosh hexadecimal file editor that handles both data and resource forks.
   http://hexedit.sourceforge.net/

J
   A multifile, multiwindow customizable editor featuring syntax highlighting and enhancements for Java, C, C++, XML, HTML, JavaScript, Lisp, and Perl, with FTP and HTTP support written in Java.
   http://armedbear.org/

Jed modes and scripts
   Some scripts for customising and enhancing the JED editor using the SLang scripting capabilities.
   http://www.paneura.com/~dino/

Katy
   A text editor for KDE inspired by the popular Editor UltraEdit.
   http://katy.sourceforge.net/

LDE - The Linux Disk Editor
   Disk editor for Linux, originally written to help recover deleted files. It has a simple ncurses interface that resembles an old version of Norton Disk Edit for DOS.
   http://lde.sourceforge.net/

NE, the Nice Editor
   An editor with a small footprint, featuring extended regular expression search and replace a la emacs and vi and editing of binary files.
   http://ne.dsi.unimi.it/

NEdit
   GUI-style plain-text editor for X-Windows systems. Features include syntax highlighting and C-style macro language.
   http://www.nedit.org/

NEdit Support Page
   Package to port NEdit on Windows and a package of NEdit macros to edit LaTeX files.
   http://nedit.gmxhome.de/

Nedit Macros
   A large collection of macros for use with the NEdit text editor.
   http://www.mailnet.co.uk/~marc/msl.html

Peacock
   HTML Editor for GTK+/GNOME. It supports most of basic HTML. It features session management and preview using the GtkHTML widget.
   http://peacock.sourceforge.net/

Programmers Notepad
   Windows programming editor with an integrated Hex viewer/editor.
   http://www.pnotepad.org/

QE Personal Editor
   A PE2-like editor program for Unix.
   http://www.geocities.com/linux4tw/qe/

Quanta Plus
   An HTML editor and a web development for the K Desktop Environment.
   http://quanta.sourceforge.net/

REd0
   A text editor written in TCL/Tk, meant to be platform-independend while still using the host systems available features.
   http://red0.sourceforge.net/

SETEDIT
   Text mode editor to supersede Borlands BC++ editor with a number of enhancements. Available for DOS and Linux.
   http://setedit.sourceforge.net/

Scintilla and SciTE
   Download, screenshots and documentation of a free source code editing component for Win32 and GTK and an editor based on this component.
   http://www.scintilla.org/

Shed
   Easy to use hex editor written for Unix/Linux using ncurses, with a friendly pico-style interface.
   http://shed.sourceforge.net/

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/

The JED Editor Page
   Text editor for Unix, VMS, MSDOS, OS/2, BeOS, QNX, and Win9X/NT platforms. A macro language and modes for different editing tasks are available.
   http://www.jedsoft.org/jed/

Tinn
   A free text editor that trys to address some of Notepad's limitations without getting too big. It is written in Delphi 5 using the TSynEdit components.
   http://tinn.sourceforge.net/

Tkoutline
   A cross-platform outline editor written in Tcl/Tk.
   http://tkoutline.sourceforge.net/cgi-bin/wiki

Vigor
   Has all the features of traditional Unix vi, plus the friendly and helpful Vigor paperclip assistant.
   http://vigor.sourceforge.net/

Vim online
   Resources, tips and news for the Vim community.
   http://vim.sourceforge.net/

Webniac
   A multilingual open source webpage editor published under GNU's GPL.
   http://webniac.futureality.net

WinMacro
   Macro recorder and player (C++) [Windows].
   http://geocities.com/win_macro

Xcoral
   A text editor for X-window (UNIX only) , with a built-in C/C++/Java code browser and a C interpreter. Beside a screenshots and a features sections there is a download area and a page with instructions to build from the source.
   http://xcoral.free.fr/

ZED
   Small editor with features for programmers.
   http://zed.c3po.it/

Zile is Lossy Emacs
   An Emacs clone useful for small footprint installations (like on floppy disk) or quick editing sessions. Available are a description of the features, information about how to get Zile, links to the documentation and screenshots.
   http://zile.sourceforge.net/

gEdit
   Lightweight but powerful text editor of the GNOME project.
   http://gedit.sourceforge.net/

jVi
   jVi is a small subset of vim which is pluggable into JBuilder.
   http://jvi.sourceforge.net/

poEdit
   A cross-platform gettext catalogs (.po files) editor. It aims to provide more convenient approach to editing catalogs than launching vi and editing the file by hand.
   http://poedit.sourceforge.net/