You can get an earlier version that runs on VMS as well. There are loads of features, including mouse support, that are too numerous to list here. Xenon Editor Xenon is a X-Windows editor that is supposed to be small and fast. It has unlimited undo and redo, and can handle multiple files in multiple windows. To get it to run, you need Linux, SGI or possibly other Unix implementations.
Source code is provided.
A programmer's editor complete with syntax highlighting. The program is currently still under development, and it lacks documentation. This is the well-known GNU Emacs editor. Some swear by it, others detest it and many flame wars have been fought by its adherents and its detractors. It is supposed to be very configurable, and supports a number of computer languages.