Yeah, that's the main issue here. There's always the 30-day trial to start with. I was actually going to write Xilinx and see if they are willing to contribute some ISE licenses to this project, provided that it is properly open sourced. I wouldn't write them however until we have a clearly stated project license type in the first post, or a webpage. Xilinx seems to support educational and non-commercial institutions, I was able to find some references to Xilinx license donations.