So as you should all know by now, Steam and TF2 are now available on Linux - the Open Source operating system!
There are some great advantages to using this method of playing, such as a higher average framerate.
After having a quick look through the Steam Powered User Forums, I saw that the user Lansing has come up with a tutorial on installing Linux (Ubuntu) to your Windows system via VirtualMachine!
I’m working on it myself just now, and I’ll check back once/if I get it working properly!
You can also get VirtualMachine on a Mac OS, but I’m really not sure how similar it is to install.