You can have the source to MultiLaunchBox if you want a base for a simple Mac application.
I was going to look into making MLB available on the pc with the ability to talk to Mac (MLB is already network ready for Macs using Bonjour).

But with ISBoxer being so awesome, I gave up on all Mac coding and just bootcamped to Win 7.

If you google Mac Virtual Machine (or something like that), you find information on creating a Mac OS VS on PC.
I think you need a legal copy of Snow Leopard though. Not sure if Lion works or not. Since I no longer have a mac desktop for development I use the VM for playing around with.