Open Source CPU -- OpenRISC

Linux 3.1 - Linux Kernel Newbies
http://kernelnewbies.org/Linux_3.1#head-37c60fa1253db74ce7d224718a71f5836bd5be09

OpenRISC is an Open Source CPU from the OpenCores project that brings to the world of hardware all the same advantages that Open Source software has known for so long. The aim of the project is to create free and open source computing platforms available under the GNU (L)GPL license, and a set of free, open source implementations of the architecture and open source software development tools, libraries, operating systems and applications. The implementation merged in this release is the 32-bit OpenRISC 1000 family (or1k).

OR1200 OpenRISC Processor - OR1K :: OpenCores
http://opencores.org/or1k/OR1200_OpenRISC_Processor