Mass domain checkHello

Hello guys,i am looking for any program that check mass amount of domains if are available or not for registration.I am looking for tool that can check more than 50,000 domains.
Thanks in advance.

I know some that can check up to 50 domains... you would need to automate the process somehow and use some proxies.

I have started developing such a tool some time ago, but don't have too much time to finish it.