Not only a working O/S, but a complete suite of open-source apps that are compatible Windows apps you use now (e.g. Open Office), and device drivers that automatically know how to work all of your hardware. Better ease of use than Windows. Way better. And much perkier performance. Anons who try Linux probably won't be able to go back to Windows. The contrast is that huge.
Well crawling back into my hole now b/c no one cares.