Xenon is a simple X-based text editor which is very handy for things like
editing source code, system configuration files, scripts and whatever else
is an ASCII text file.

Features include:
  * Speed, simplicity and low memory use.
  * Search, substring or regular expression
  * Unlimited undo/redo.
  * Display of line numbers, jump to line number
  * Some X resource configuration: mostly command keys, some colours
  * Man page!
  * Some error dialogs.
  * Multiple files in separate windows.
  * Open multiple files from the command line
  * Run Once (only one process per uid and X connection IP number)

WWW: http://sydney.proximity.com.au/~ben/xenon/