This one is new to me, the OpenFire soft processor project –
The OpenFire soft processor is an open source Verilog implementation of the Xilinx MicroBlaze processor. Like the MicroBlaze, the OpenFire is a 32-bit RISC processor based on the DLX architecture by Hennessy and Patterson. The OpenFire was developed by Stephen Craven, a PhD student at Virginia Tech, specifically for configurable array research. As such, certain features of the MicroBlaze were not initially implemented. The original implementation of the OpenFire lacks interrupts, exceptions, debugging facilities, and Local Memory Bus and On-chip Peripheral Bus interfaces. These interfaces were omitted from the original release in order to facilitate an ultra-minimal implementation for the OpenFire.
OpenFire soft processor – Link.