3ivx MPEG-4 is a mature industry standard video compression system which
enables the transmission and storage of video, which would otherwise be too
large to store or transmit. 3ivx MPEG-4 5.0.5 for Mac OS X consists of MPEG-
4 Video and File Format components for authoring and playback of MPEG-4
media.
Compared to Apple MPEG-4, 3ivx MPEG-4 5.0.5 encodes up to twice as fast,
producing the same quality video at half the size.

Why should I install 3ivx?
The 3ivx decoder components play back most MP4, M4A, 3GP, MOV and AVI files with MPEG-4 Video and MPEG-4 AAC Audio. Supported MPEG-4 variants include DivX 3 through 6, Apple MPEG-4 and Xvid. The audio decoder can play MPEG-4 High Efficiency and Low Complexity AAC audio encoded by Nero AAC, iTunes and others. The components work with Windows Media Player, the QuickTime Player and any other compatible applications
3ivx MPEG-4 5.0.5 produces noticeably higher quality video than other decoders due to its high quality post-processing filters, and because of its core design and optimization maintains a record-breaking speed.

The 3ivx encoder components produce industry-leading compact high quality MPEG-4 Video and Audio and are distributed as plug-ins for DirectShow as well as plug-ins for QuickTime and Video for Windows. This allows you to encode MPEG-4 Video and Audio in AVI, MOV or MP4 files with the encoding application of your choice.

3ivx MPEG-4 encoded video can be played back by QuickTime 6 or 7 without the need for any additional component to be installed.

MP4 Export functionality has been added to the 3ivx Media Exporter for QuickTime, allowing easy export of high quality 3ivx MP4 files from iMovie, Final Cut Pro and other QuickTime Applications. The resulting MP4’s are directly compatible with most MP4 Players, including Apple's iPhone and AppleTV.