The LM32 _is_ a good example of open source CPU; and there's more to open source than GNU. Also, it is simply more technically appropriate
here than LEON, OpenRISC and OpenSPARC.
There was some confusion about the LM32 license (sparkled among other things by confidentiality notices left in the source files) but Lattice cleaned up most of the mess
a few months ago.
The Lattice license
" The Provider grants to You a personal, non-exclusive right to use object
code created from the Software or a Derivative Work to physically implement
the design in devices such as a programmable logic devices or application
specific integrated circuits."
So - yes, we can implement it in non-Lattice FPGAs.
There is no MMU; some people talked about building one but it did not happen. We are open to switching to OpenRISC should it become as small and fast as LM32.