This is a bit nifty. A Russian company called Alternativa are working on a 3D engine that runs in straight, browser Flash. And flipping crikey, it’s not bad.
There’s a couple of demo areas you can trudge about – a science fiction-themed bunker (with footsteps I’d swear are from Deus Ex, and I know the bleepy noises too – someone please tell me in the comments), and an outdoor ancient ruin in the sunshine. Check them out. Be a bit impressed.