Environment for editing LaTeX in Vim. Huge set of menus and shortcuts, improved syntax, compiler and ftplugin files, and recognition of \usepackage commands. http://vim-latex.sourceforge.net/
Open source LaTeX Editor written using GTK+ and based on Bluefish. Berlios project page, screenshots, forum and mailing lists. http://winefish.berlios.de/
A package with some preconfigured TeX files and tips for using TeX (primarily on Linux) which enables automatic update of the compiled (La)TeX document. It is not a self-contained editor, but uses standard tools on Linux. http://omnibus.uni-freiburg.de/~stierm/TeX/
Latex editor with syntax highlight, document structure tree view and project handling. Latex output allows direct jump to warnings/errors, Projects folders gives support for figures/graphs. (Python, Pre-Alpha) http://sourceforge.net/projects/dolatex
A simple text editor based on the script language Tcl/Tk, especially adapted to LaTeX written by Martin Strauß. Contains short description, downloads and screen shots. http://tcltexed.sourceforge.net/