Both hopl papers are available on the digital library on the acm website. Here are the free links:
History of Lisp (John McCarthy) - http://www-formal.stanford.edu/jmc/history/lisp.ps
History of Smalltalk (Alan Kay) - http://stephane.ducasse.free.fr/FreeBooks/SmalltalkHistoryHO...
Seaside (the killer app for squeak/smalltalk) - http://www.seaside.st/
