Can Rainbow Tables crack the Unix Hashes?
Unix Hashes use Salt to prevent Rainbow Tables crack it.

And I suggest to make Distributed Brute Forcer support SSE and CUDA.

Create a creative commons license (or any other "free" license) for the site and every rainbow table.

http://creativecommons.org/choose/
http://creativecommons.org/about/licenses
how about this one ? http://creativecommons.org/licenses/by-nc-sa/3.0/
this is important.

I know PHP .

If you mean DES-Hashes, theoretically possible since the number of SALTS is limited, searching the forum should yield an article w. estimates. If you mean MD5-crypt or bcrypt - no. BarsMonster is working on a distributed bruteforcer ("salty cracker") and maybe others. A way of moving uncracked hashes from one project to another has been discussed. You can use john-mpi from bindshell.net if you have some machines. Requiremens: Open-MPI and SSH. This will work rather well for DES-Hashes. schwarzwaldhacker over at the barswf-forums released a CUDA-capable DES-Cracker.

Could you implement benchmark on rcracki_mt or not ?
if PB eventually decides to improve the buy-a-table system, we really need this done.

I am curious to know what the status of the CUDA support in rcrack_mt is. Any updates? Thanks!

So noted, do you mind adding a feature request to the bug tracker at rcracki.sourcefore.net?

done

I don't see why... this is a trivial space to search.

With per-position character set support (the Cryptohaze multiforcer has this), this is a 10-20 second space to search on a modern GPU.