Have you had a look at Textmate? It uses PGP in an interesting way, http://sigpipe.macromates.com/2004/09/05/using-openssl-for-license-keys/#more-5 http://sigpi

Have you had a look at Textmate? It uses PGP in an interesting way, http://sigpipe.macromates.com/2004/09/05/using-openssl-for-license-keys/#more-5 http://sigpipe.macromates.com/2004/09/05/using-openssl-for-l...