As you may know, Canonical is going to replace the X.org server with Mir, a display server created by themselves, in order to use it on both Ubuntu Touch and Ubuntu 13.10 Saucy Salamander and higher.
Canonical aims to get Mir ready until the 29th of August, when it gets in the Feature Freeze state.
For the bleeding edge technology enthusiasts that use one of the daily builds of Ubuntu 13.10 Saucy Salamander, Mir can be easily installed, because it has been officially added to the official repositories.
To install and test Mir on Ubuntu Saucy, just do:
$ sudo apt-get update
$ sudo apt-get install mir-demos unity-system-compositor
If everything goes well, you should not even notice any difference with Mir. At the moment, Mir is buggy and unstable, since the developers didn’t start the bug-fixing yet.
For more information on Mir, see this articles.