latexdiff is a Perl script, which compares two latex files and marks up significant differences between them (i.e. a diff for latex files). Various options are available for visual markup using standard latex packages such as "color.sty". Changes not directly affecting visible text, for example in formatting commands, are still marked in the latex source.
MajorCool is a CGI script written in Perl that provides a Web interface to Majordomo v1.9x*. It is intended to run co-located with the Majordomo program (ie, both list-server and Web on the same host). Employing a variety of Web/GUI techniques such as Balloon Help, Per-User Preferences, and MouseOver cues, MajorCool puts a friendly face on top of the Majordomo list management processes.