Boxee is home theater PC software that makes watching streaming and downloaded media on your TV a real delight. It's really popular for people who have Mac Minis hooked up in their living rooms, as it can be installed right on top of OS X. That is to say, you need a computer in your living room to run it.
That won't be the case forever! In fact, Boxee just announced that it's got a deal lined up with a hardware partner to release a Boxee Box for your living room next year. So instead of buying a computer just to run Boxee, you'll get a device designed exactly for your Boxee-related home theater needs. Exciting!