An extension of the GNU Emacs VC package which understands the ClearCase configuration management system. This package is not officially supported, but the author is willing to fix bugs in it as time permits.
Constraint Unification Prolog (CUP) developed by the Institute for New Generation Computer Technology (ICOT), Japan. Originally written in C under Unix, MacCup is for Macintosh, DJCup for MS-DOS, with both implementations released as free software.