Putting together a home-theater PC and don't have a spare Windows license kicking around? Looking for a slick 10-foot UI to run on top of an existing operating system? Check out XBMC, which has now reached version 10.0. Dubbed Dharma, the latest version of XBMC is quite the milestone for a project that began aboard the original Xbox console. 10.0 won't run on an old Xbox, but versions are available for Windows, OS X, Linux, and even the Apple TV. XMBC can also be downloaded as a standalone live CD that runs off optical media or a USB drive.
Dharma brings an numerous changes to XBMC, the most important of which seems to be the addition of an add-on manager. Previously, users had to scour forums and deal with separate downloads to add skins or other features to XBMC. In the words of its developers, "those days are over." The add-on manager allows you to change the look and functionality of XMBC without leaving the couch or dropping the remote.
On the playback front, XBMC 10.0 adds WebM/VP8 codec to its already impressive list of supported formats. The software's support for hardware-accelerated video decoding has also been expanded to include Broadcom's Crystal HD decoder, and the Live CD has been optimized for Nvidia's next-gen Ion GPU.
I've used XBMC on and off since its early Xbox days, and I have to admit that I've missed it since moving my home-theater PC over to Windows 7 and Microsoft's MCE interface. XBMC's interface feels snappier and more refined, and its music visualization plugins are light years ahead of what comes bundled with Windows. Dharma will probably lure me back to XBMC before long, especially if the add-on manager is as slick as it sounds. Already, the developers claim they're seeing an average of 50,000 add-on downloads per day.