Mental Omega: Almost Perfect Yuri's Revenge is a free unofficial expansion pack for Command & Conquer Red Alert 2 Yuri's Revenge (from Westwood Studios), which retells and continues the storyline of the original game. Enhanced with Ares DLL, Mental Omega 3.0 strives to bring new features to Red Alert 2 Yuri’s Revenge.
You asked and we (finally) listened. A new skirmish/multiplayer game mode in Mental Omega 3.0 Beta Revision 2 will allow you to construct all subfaction technology regardless of which subfaction you choose. Complete Allied, Soviet or Epsilon arsenal will be at your disposal in this mode.
On a less related note - while some Command & Conquer online services are going down soon, Red Alert 2, Yuri's Revenge and Mental Omega will not be affected. We still recommend using CnCNet to play Mental Omega on multiplayer: Mentalomega.com
Unholy Alliance is still in, although it is now renamed to AllTech.