rt is a 1990 regression testing library that is used by some older software.

Paul Dietz has added some features to rt for his GCL ANSI Test Suite. These extensions have been incorporated into sbcl's sb-rt package and Kevin Rosenberg's cl-rt Debian package.

Kevin Rosenberg's git repository: http://git.kpe.io/?p=rt.git;a=summary

Old version from the CMU AI Repository: http://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/lisp/code/testing/rt/0.html