The University of Cape Town in South Africa is developing an open source SDR project known as RHINO, which stands for Reconfigurable Hardware Interface for computiNg and radiO.
Reconfigurable Computing is an attractive computational technology, allowing an almost limitless set of possible solutions to any particular problem. It does this by providing an effective compromise between the performance of hardware and the flexibility of software.
Software Defined Radio is a discipline that has benefited greatly from this technology, allowing for complex, high speed digital signal processing algorithms to be implemented in cost effective field programmable gate array technology.
The Rhino Project is an Open Source effort at the University of Cape Town in South Africa to provide a hardware platform and software toolchain for SDR which is both easy to use, easy to learn and affordable to a broad audience. It is hoped that this effort will consolidate and enhance the teaching and research resources available for SDR.
Their hardware design is based on a Xilinx Spartan-6 FPGA teamed up with an ARM Processor running BORPH Linux. You can view the hardware schematic and project detail PDF on the RHINO project info page.