two questions about spartan/xilinx devices??

1. Have you positively check any free '51 cores for spartan/xilinx devices??
Ive tried some but have big problems with implementing.
2. Can you give me any links with examples - projects with spartan devices??
Not inside - i need some power suply method to see so protel or other.
Greetings
Thx in advance
5hinka