These are free of charge, but they are not free as in free-speech.
If you use these:
1) you have to run Windows (I use Linux)
2) you have to use their devices, and moving your HDL designs to another
company's "free" tools may not be as cut and past as you hope.
AND
3) any improvements you can think of, or features you would like, probably
can't be integrated, because you don't have the source code.
Most of the chip companies give gratis software, and refuse to give the
information about the chips for anyone to write their own tools. Which
to some of us is the heart of the problem.
Yours
Ian

>Altera also has free tools on the web check out
>
>http://www.altera.com/products/software/sfw-quarwebmain.html
>
>http://www.altera.com/products/software/free/fre-emax_baseline.html
>
>and free synthesis
>
>http://www.altera.com/products/software/free/fre-download_0.html