From its website:
LEON2 is a synthesisable VHDL model of a 32-bit processor compliant with the SPARC V8 architecture. The model is highly configurable, and particularly suitable for system-on-a-chip (SOC) designs. The full source code is available under the GNU LGPL license, allowing free and unlimited use in both research and commercial applications.
LEON2 was developed by Gaisler Research, Sweden, for the European Space Agency.