screen for X11, remote access for MS Windows and Mac OS
xpra started as 'screen for X11', allowing users to forward X11 applications running on remote computers, seamlessly (the windows forwarded to the client behave just like local applications).
It is used locally for application isolation, or for remote access. The compression engine self-tunes automatically for any type of network performance, using a large variety of picture encodings.
With its proxy server it can also be used to provide a single point of entry for multiple servers.
xpra now runs on all major distributions, including MacOS, MS Windows. It has a builtin web server providing an HTML5 client. Multiple users can connect to the same session simultaneously.