Sony's ACID Pro (formerly Sonic Foundry's ACID Music) is a popular loop-based music production application. Supported by systems running Windows 2000 and XP (no Mac OS support), it is a powerful audio-editing
tool that can stretch or compress sound without altering its pitch. ACID Pro
includes lots of DirectX audio effects, employs powerful new Media Manager technology, Beatmapper and Chopper tools, as well the ability to mix in 5.1-channel (24-bit, 192kHz) surround.