The DivX is a video compression/decompression format which allows videos to be compressed to very small volumes with a quite reasonable loss of quality. Thus, the DivX format makes it possible to store a complete film on a 650 or 700 MB CD-ROM.
The DivX format was developed in 1999 by a 27-year-old French developer, called Jerome ROTA, starting from Microsoft’s MPEG-4 v3 codec. Indeed, the MPEG-4 codec, with which the beta release of the Windows Media Player was equipped as a standard was perfectly operational, but at the time of the release of the official version it no longer worked properly, which is why Jerome ROTA decided to correct it as well as to add the possibility of compressing sound with MP3 format; he thus developed what would become the "DivX ;-)" format (D andX being uppercase letters), an “eye wink” directed at the divx system (Digital Video Express) whose purpose was to protect DVDs against illegal copying, but which was never a great success since the DVDs thus protected became illegible after some time.
The codec, up to its 3.11 alpha version, was an Open-Source project (called OpenDivX and developed by Project Mayo) based on a “hack” of the Microsoft codec. In 2001, Jerome ROTA founded the company DivX Networks in order to produce a new entirely rewritten proprietary codec to become free from any obligations regarding Microsoft rights, which led to version 4 of the codec, which was called DivX4.
As from version 5 of the codec (called DivX5), the DivX compression codec became a commercialized software (DivX®) with a free version (DivXTM) containing spyware.
The XviD format is an Open-Source implementation of the Divx codec, developed as from 2001, at the time when the original DivX format (developed by the Project Mayo) team) became a proprietary format. The XviD format thus offers a very high quality compression.
The 3ivX format is an alternative video compression format which allows MPEG-4 compression in APPLE QuickTime files (.movextension), which makes it particularly appreciated by Macusers. The 3ivX format however offers a much lower quality than the DivX format.
The DivX format (starting from version 4 and higher), as well as the other video formats, are not illegal themselves, but their use may be due to the copyrights that may apply for the compressed works.
Thus, Articles L122-5-2 and L211-3 of the Intellectual Property Code authorize the making of private copies of a legally acquired original (for example a rented DVD), for private use and within a family circle. A tax was thus applied to storage materials (CD-R) in order to compensate for the losses of the artists caused by this right to a private copy.
On the other hand, the diffusion (distribution through the Internet, sending by parcel service or by any other means, or file-swapping software) and the remote loading of works protected by copyrights is forbidden by the law and punishable as counterfeiting.