Movie saved or formatted in Apple's proprietary QuickTime format; may use one of many types of codecs to compress the file, including the H.264 video codec, which uses a high-efficiency compression algorithm; H.264 support was introduced with QuickTime 7.0, which was released with Mac OS X 10.4 Tiger and is also available with QuickTime for Windows. Most QuickTime movies can be played back by earlier versions of QuickTime Player, but QuickTime 7 or later is required to play back H.264-encoded video files. QuickTime movies may also use the .MOV extension, which is especially common on Windows-based computers.