The Razor database (http://razor.sourceforge.net) by Vipul Ved Prakash and Jordan Ritter allow Unix clients to work out of the same database used by the commercial customers of the Cloudmark system. This is a HashSharingSystem.
When SpamAssassin 3.1.0 was released, the code used to access the Razor system (now a plugin) was disabled by default due to our policy of only using services that are 100% freely available to everyone, which Razor was not. The usage policy changed as of 3/13/2006 which makes the service freely available again:
Razor2 Service Policy V2.0 March 13, 2006 Razor2 agents connect to the Cloudmark Collaborative Security Network to report spam and check for fingerprints. Cloudmark provides free and open access to the CCSN but reserves the right to deny access to anyone.