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Unreal Engine 3 (UE3) is Epic's next-generation technology, intended for games shipping on Xbox 360, PlayStation 3, WiiU, NGP, iOS, Android, Flash, Mac and the latest PC graphics hardware. In order to support a cutting-edge feature set, UE3 will not be backwards-compatible with pre-DirectX 9 hardware or previous generation consoles. UE3 is licensed separately from UE2, and it also has separate support web pages, email lists, IRC channels, etc. This code has been proven in Gears of War (www.gearsofwar.com) and in Unreal Tournament 3 (formerly Unreal Tournament 2007).
Unreal Engine 2.5 (UE2.5) is the latest engine version for previous generation hardware. This code has been proven in Unreal Tournament 2004 (www.unrealtournament.com), and is the recommended starting point for new licensees seeking hardware flexibility not available with UE3. Aside from critical fixes, we are no longer developing software updates and features for UT2004; but any updates will be made available to licensees as well.
Unreal Engine 2 (UE2) supports DX8 and runs on the following platforms: PC, Mac, Linux and the following consoles: Xbox, and PS2. This code has been proven in Unreal Tournament 2003 (www.unrealtournament.com), which was later transitioned to UE2.5. UE2 is no longer under active development, and Epic plans no further games in-house using that technology. The final drop - UE2 v2227, available on the CodeDrop2227 page - includes all bug fixes that have occurred since build 2226, as well as a few enhancements for supporting other platforms. We will of course continue to support all licensees using UE2.
Unreal Engine 2X (UE2X) is a highly optimized version of Unreal Engine 2 only supported for Xbox, made for Unreal Championship 2 (www.liandriconflict.com). The code is available to all Xbox project licensees. No further development is planned for UE2X after UC2, so that we may concentrate our efforts on supporting next-generation consoles through UE3.