Borgshare is a P2P software.
It's completely serverless and it manages user lists to have a fully directional communication.
Each user can contact every one in every moment (obviously after a user status check - if he is online).
Main characteristic is the use of a simple web server that generates html code about users, files to share, downloads and so on.
This is the simple and the effective way to let users use the program: they can use a normal web server to interact with the software.