The arrival of XBMC on the Xbox was a significant moment in the evolution of home media centres. But the really big shift came when XBMC moved from being a console-only offering to a program that would run on multiple platforms.
This wasn't a speedy process by any means. The first XBMC release came out in 2004, and the second major version in 2006. It wasn't until November 2008, with the 'Atlantis' version of XBMC, that the vision of cross-platform availability became a reality for anyone than the more dedicated alpha and beta testers. Nonetheless, XBMC quickly took root as a popular alternative to commercial rivals such as Windows Media Centre or Apple TV, offering greater flexibility in format playback and the ability to customise your system in pretty much any way you wanted. Offering options for Windows, Mac, Linux and (eventually) even the Apple TV box, XBMC meant you choose pretty much any hardware/OS combination you liked
As we alluded to in the first instalment of this series, one powerful reason for making the shift was that the Xbox, by its very nature, is a difficult platform to develop open source software for. Not only are development processes for other major OSes more thoroughly documented, there's no restriction on distributing easy installers for them. That meant that despite the Xbox's pivotal role in establishing the project, over time it became a secondary platform rather than the prime driver.
By the time the first Atlantis release appeared, XBMC had also inspired a number of spin-off projects -- including the formation of a company called Boxee, which released the first alpha version of its own software in June 2008. And that's where we'll pick up the story tomorrow.