MACPeople

Can my friends play on WINbolo that use a MAC os ?

Not without installing Windows XP or an emulator on the Mac computer.

jhood is correct. There are two bolo 'clones' available for OSX: nuBolo and XBolo. Neither is compatible with winBolo :-(

I have bootcamp and XP installed on my mac and it plays winBolo very well.

On the OSX side, it's virtually impossible to find an active game of nuBolo. XBolo games are kinda rare, but if you join their irc channel you might be able to stir up a game. Some of the developers have bots that can make a game between 2 people more dynamic.

Good luck!