The acronym ACE, depending on context, can refer to: *Accumulated Cyclone Energy, a measure of the activity of Atlantic hurricane seasons*Adaptive Communication Environment, an open-source class framework*Advanced Computing Environment, a defunct initiative to define a "new PC" based on MIPS CPU's instead of Intel x86*Advanced Composition Explorer, a NASA satellite*Air Combat Emulator, a 1980s computer game for the Commodore 64 home computer*Altamont Commuter Express, a commuter train ...