http://www.xemacs.org

XEmacs
The famous Emacs editor/IDE. Syntax coloring, automatic indentation, multi language (C, C++, Java, Ada, Python, Perl, Lisp, HTML, asm, ...), incremental search, tag search, many modes (compile, gdb, mail, news, browser, shell, ...), and more and more and more.

Well, you don't need anything else than... Emacs...