At Adobe’s annual Adobe Max conference today, Epic Games’ Tim Sweeney made an announcement demonstrating that Unreal Tournament 3 can running entirely in Adobe Flash with the Unreal Engine 3.
A large number of the games running on Flash are 2D experiences, but with the Unreal Engine running inside of it, this opens the door for impressive-looking 3D games to run inside a browser, as well as for existing (or future) Unreal Engine games to easily be made playable on a vast array of computers. By the same token, it also presumably opens the door for these games to be playable on tablets and other Flash-capable devices.
Unreal Tournament 3 was the game shown running inside Flash today. Although it didn’t look quite up to par with what you’d see by running the game in a traditional fashion with the graphics cranked all the way up, it still looks a good deal better than the vast majority of anything you’d typically see running in Flash.
Source: http://www.1up.com/news/unreal-engine-3-can-run-in-browser-flash
http://epicgames.com/community/2011/10/unreal-engine-3-support-for-adobe-flash-player-announced/