AMDOverdriveCtrl is this new open-source utility for OverDrive overclocking of Radeon hardware under Linux. It's not an official program from AMD but was written by a Linux user against AMD's Display Library API, which they released for Linux in 2009. The program was announced this morning in our forums.
The open-source AMDOverdriveCtrl program allows controlling the GPU and memory frequencies like the AMDCCCLE/aticonfig programs do as the official ways of overclockng, but it also allows for manual voltage adjustments, manually setting the graphics card's fan-speed, other fan control modes, application profiles, and long-term thermal/fan-speed monitoring. With the Catalyst driver and AMD's official utilities it's possible as well to read the GPU core temperature and fan speed on supported ASICs, but this application looks to take it a step further. The program provides a graphical user-interface via wxWidgets.
As this program is written against the AMD Display Library API, it should work out and be a cleaner / more stable solution (albeit it's not officially supported by AMD) way of overclocking your Radeon HD 2000/3000/4000/5000/6000 series GPUs compared to a program that's developed via community reverse-engineering. Though with the program's dependence on the ADL library, it will only work with the Catalyst driver. The open-source ATI/AMD Linux graphics drivers do not support the AMD Display Library so don't expect to magically overclock your graphics processor if using anything but the Catalyst binary blob.
This program can be discussed in our forums and downloaded from SourceForge.