use old laptop as universal remote

I nave an old IBM laptop that I want to turn into an IR universal remote for my home theater. I know the IR transmitter isn't very powerful, but I have a way of getting around that. The thing that I'm looking for is a piece of software for the laptop to drive the IR. It also needs to be either free or VERY cheep, because I've already spent a lot of money on my theater. But go ahead and list all options anyway. The laptop currently runs Win2k but I can EASILY change that to linux if needed.