XvMC stands for X-Video Motion Compensation and allows MPEG decoding to be offloaded to the GPU. Right now MPEG is the only format supported, but Intel's Keith Packard mentioned at FOSDEM that on his agenda is bringing more video standards to XvMC. Intel is also the company behind VA-API, which is a new Video Acceleration API with multiple standards support, but it's currently not ready for prime-time.
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via Twitter or contacted via MichaelLarabel.com.