That's not really new.

The only real choices for this kind of thing are Linux or WinCE.

- VxWorks is more of an industrial control thing, it's extremely reliable, but pricey and only just got graphical support.

Linux has been the primary OS for home electronics for at least a decade, because it's very lightweight, easy to customise and supports a vast range of hardware.

Thus if you choose LInux, you can choose cheaper hardware as well as having a free licence.

- You'll probably want development support either way, and that costs about the same.

When you go mass-market, the development cost becomes almost irrelevant, but the per-device cost becomes critical.

Saving 10p of FLASH or RAM per device saves you £100K in a run of a million. Imagine saving a $10-$25 licence fee...

The other fun fact is that WinCE6 is end-of-life, and according to the Windows Embedded Compact site it appears that you can't run WinCE6 programs under WinEC7 - it now wants Silverlight.

So for BT to keep shipping volume they'll have to redevelop everything anyway, so better pick something that supports their existing hardware - and PACE already have experience with Linux in their other STBs, probably on near-identical hardware.