CSpace

CSpace: "CSpace provides a platform for secure, decentralized, user-to-user communication over the internet. The driving idea behind the CSpace platform is to provide a connect(user,service) primitive, similar to the sockets API connect(ip,port). Applications built on top of CSpace can simply invoke connect(user,service) to establish a connection. The CSpace platform will take care of locating the user and creating a secure, nat/firewall friendly connection. Thus the application developers are relieved of the burden of connection establishment, and can focus on the application-level logic!

CSpace is developed in Python. It uses OpenSSL for crypto, and Qt for the GUI. CSpace is licensed under the GPL."