Xpra is an open-source multi-platform persistent remote display server and client for forwarding applications and desktop screens.

It gives you remote access to individual applications or full desktops.

On X11, it is also known as screen for X11: it allows you to run programs, usually on a remote host, direct their display to your local machine, and then to disconnect from these programs and reconnect from the same or another machine, without losing any state.

It can also be used to forward full desktops, from X11 servers, MS Windows, or Mac OS X.

Xpra also allows forwarding of sound, clipboard and printing services.

Sessions can be accessed over SSH, or password protected over plain TCP sockets with or without SSL.

Xpra is usable over reasonably slow links and does its best to adapt to changing network bandwidth constraints.

For more details see here, you can find the source here.