Command & Conquer: Generals is a real-time strategy video game and the seventh installment in the Command & Conquer series. It was released for Microsoft Windows and Mac OS operating systems in 2003 and 2004. While the Windows version of Generals was developed by EA Pacific and published by EA Games, the Mac OS version was developed and published by Aspyr Media. In the game, the player can choose from three different factions: the United States, China and the Global Liberation Army (GLA). Generals utilizes SAGE (Strategy Action Game Engine), an extended version of the Command & Conquer: Renegades 3D engine. An expansion pack, entitled Command & Conquer: Generals – Zero Hour, was additionally released for PC in 2003, and for Mac OS in 2005. Both Generals and Zero Hour were met with highly positive reviews. A sequel, Command & Conquer: Generals 2, was in development, until it was repurposed to a free-to-play game known as simply Command & Conquer. The new game was based around the Generals franchise and was cancelled on 29 October 2013 by EA after negative feedback during the closed Alpha test.