RetroShare is a free program that combines Chatting, Instant Messaging and filesharing using connections limited to trusted friends, not to every possible peer on the internet. All is serverless, opensource and encrypted. You can search for files, which all your friends share.
Friend to Friend (F2F) is a new paradigm after peer-to-peer (P2P). P2P connects you for sharing with neighbors all over the world, while F2F maintains connections only to your trusted friends.
Because RetroShare is a private filesharing network, it doesn’t really matter how many people use it – the network will function well with only a couple of friends in the Messenger. Of course, the amount of material and the network availability both improve as your friendlist grows. Remember that a RetroShare connection allows direct secure communication only between the two peers/friends, and no one else. The amount of available shared files increases as you Instant Message with RetroShare to more and more friends. As you connect to more people the AutoDiscovery system introduces you to the friends of friends. You can accept or deny to connect to friends of friends (one hop only is offered!!) This allows the network to expand and develop if you have not enough friends to be your trusted friends.
Once you have swapped your PQI-Certificate with your friend (a certificate is generated for each user when they start up the program for the first time) and are both AUTHenticated, (if port, IP, firewall and router settings are okay) you can connect automatically with your friend whenever you start an online-session.
Auto-Login is a Windows only feature at the moment.