[CentOS] the "official" lightweight desktop environment for CentOS?

I want to build a dedicated MythTV box using CentOS5. I need a 
lightweight desktop environment, something extremely simple that does 
not use much memory. Gnome and KDE use way too much memory and are too 
complex for what I want to do.
The system will login automatically to a certain account after booting 
up. After the automatic login, it will start immediately the MythTV 
frontend full-screen. If the frontend dies, the desktop needs to logout 
/ log back in automatically. No other application will run on this 
machine, only mythfrontend. There will only be one account. Think of it 
as a single-purpose appliance, not a regular computer.
Whatever I use as the desktop environment, it needs to be pretty 
standard - either included in the distribution proper, or in one of the 
major repositories. It must be very trivial to enable, with no hacking 
required to the OS. It must play well with mythfrontend, I don't need 
any compatibility issues. It must be a stable, reputable software.

Which desktop environment would you recommend based on the requirements?

-- 
Florin Andrei

http://florin.myip.org/