I haven't tried it, but FreeS/wan seems pretty popular.
http://www.freeswan.org/
At 07:45 AM 11/20/2002 +0000, SB CH wrote: >Hello, all. Received on Fri Nov 22 23:15:40 2002
This archive was generated by hypermail 2.1.8 : Wed Aug 23 2006 - 14:03:23 EDT