Boxee suddenly became available for OS X 10.4 users, here's your sign. The underpinnings of the Apple TV are indeed based on Tiger, thus paving the way for Scott Davilla, a developer for the aTV-bootloader project, to announce that Boxee and XMBC can now be installed on Apple's set-top-box. In order to take advantage, you'll need the aTV Flash bootloader on a bootable USB drive, an Apple TV and the software in the links below. Currently, things are setup to run on Mac only, though PC / Linux versions are promised for next week. After signing up for a Boxee invite, jump on past the break for the step-by-step guide to getting this going.