It is great that Interlisp-D is being kept running, and kudos to everyone making it happen.
Almost everyone knows about Smalltalk, yet there are lots of interesting stuff coming out of Interlisp-D, Mesa (XDE) and Mesa/Cedar, which also deserve more widespread knowledge.
> We identified discrepancies in Medley’s Common Lisp implementation by testing against the examples in Practical Common Lisp by Peter Seibel.
Huh? While PCL is a great introduction text with practical examples, I doubt its suitability as ANSI CL standard compliance benchmark; it surely wasn't meant as such. Why not use Paul Dietz's ANSI test suite?