It's actually dual-licenced GPL and an alternative where you don't get the so-called "viral" properties of the GPL, but changes to the code still get returned to the project, kind-of LGPL-ish.

http://x264licensing.com/

That seems to suit what Cisco are doing here, but a Cisco representative claimed that when they suggested just using x264 that it was shot down by Mozilla (possibly because Mozilla shared the common misconception than x264 is GPL-only?)