Tcl Scripting language with graphics toolkit Debuggers DDD Cool debugger that sports a Motif interface. Diff tkxcd Diff interface like PureAtria's xcleardiff. My new favorite. My old favorite. Cxref Generates HTML cross references from C programs.
Editors emacs Do anything.
NT Emacs Emacs for NT users, too. XEmacs Another form of emacs. The editor we love to hate. Nedit Good GUI editor. I had trouble connecting to this.