Matthias Hoelzl:
He reported and fixed COMPILE's misbehavior on macros.
+Espen S Johnsen:
+ He provided an ANSI-compliant version of CHANGE-CLASS for PCL.
+
Arthur Lemmens:
He found and fixed a number of SBCL bugs while partially porting
SBCL to bootstrap under <some other Common Lisp system -- LispWorks