CMOSexod.com
For advanced hobbyists: share free microprocessor and DSP IP cores written in Verilog or VHDL.
E-Risc
Project to design and implement scaleable RISC microprocessor for embedded applications. All architecture and source code to be released under GNU General Public License, or a slightly modified version that includes hardware, not only software.
Google Groups: Free SPARC VHDL model available
Initial announcement of the GPLed LEON SPARC architecture.
LEON-1 VHDL model
Functional SPARC compatible processor core integer unit. Runs on Altera, Mietec, Temic MG2, Xilinx. Developed for space missions. Implemented as a highly configurable, synthesisable GPL VHDL model.
picoJava Core
A core is the central component of a microprocessor or controller chip. Chips using picoJava core are ideally suited for consumer electronic products running Java applications. By Sun Microsytems, Sun Community Source License.
Press: Sun Extends Community Source Licensing to C
Sun Microsystems announces: for research uses, it extends its new Community Source Licensing model to picoJava and SPARC architectures; the first time a company made major microprocessor intellectual property available via open licensing.
STM
32-bit, 2-way superscalar RISC processor, designed in a HDL. Source downloads. This one is actually working.
The Freedom CPU
Mainly dedicated to purely SIMD superpipelined 64-bit RISC CPU, and the sources distributed under the terms of the GNU licence.
TRON VLSI CPU
32-bit microprocessor architecture developed to serve as the main hardware building block of the real-time TRON Hypernetwork (Highly Functional Distributed System: HFDS), which is the ultimate goal of the TRON Project.