REXX, SPF, Internet drafts
Version 1.6 of the MD5 test suite covers RFC 5034 (Digest-MD5 for POP3), RFC 4122 (UUID version 3), and an old RFC 1910 example. The POP3 example belongs to the MD5-sess series.
The UUID example is apparently wrong, it swaps the byte order unnecessarily. Examples published by python.org and ossp.org agree with that theory, I'll submit it as erratum.