I'm a Windows user/developer itching to start diving into the *NIX world and Mac OS software development. What software (both paid and free) would allow me to install/easily run other OS (Linux, Mac OS X, Unix, whatever) all on the same machine.
I'm willing to upgrade my computer (8GB of RAM, 8-core) if needed be.
If you could point me to a link of simple tutorial / book that'd be great so I could study on my own.