Checkout Minivend (Score 1)

You should take a look at Minivend http://www.minivend.com. The license is GPL, it is extremely feature rich and flexible. Written in Perl, it has its own tag system and allows embeded Perl. It supports CyberCash, SSL, PGP, database connectivity with SQL and DBI/DBD, and internationalization. There is extensive reference material available plus a new user documentation project is currently underway.