I tried to help find an answer since my other post was less than helpful.
I don't really know anything about macs either so hopefully someone can be of more help than I'm about to be.
Since this is compiled with VC++ it will only open with windows. It is open source though, so it may be possible to compile it with another similar mac friendly program. There's some info with links
here.
There's also Xcode which may work, which if I recall correctly is free if you have OS X; and may have even come with your mac. Info
here.
The only other solution I could find was a more general solution (and possibly very costly,) for running windows software on a mac. It's to use the mac boot camp utility to install and run windows xp. If your old pc had xp and you still have the disc, this may be a good free solution which will allow you to run any of your old windows only stuff. I think there's also some sort of virtual environment that would allow you to easily switch between both OS'.
Good Luck.