It took Len Shustek, chairman of the board of trustees of the Computer History Museum in Mountain View, California, 10 years to get permission from IBM to publish the APL/360 source code. Not only has he gone and done it, he’s also written a wonderful companion explanatory essay to go along with its publication. Please see: The APL Programming Language Source Code
Congratulations, Len! Thank you for your persistence.
(Special thanks to the ever vigilant Christian Langreiter for scooping this story)