What is the history of SpamAssassin?
SpamAssassin was originally imported into Sourceforge on 2001-04-20; this was pretty much the very first code for SpamAssassin. The changes can be viewed through [http://cvs.sourceforge.net/viewcvs.py/spamassassin/spamassassin/ the CVS repository on Sourceforge].
Before that, there was filter.plx; this is described at http://SpamAssassin.org/prehistory .