DivX is a brand of video codec products developed by DivX, LLC.
There are three DivX codecs: the original MPEG-4 Part 2 DivX codec, the H.264/MPEG-4 AVC DivX Plus HD codec, and the High-Efficiency Video Coding DivX HEVC Ultra HD codec.
The most recent version of the codec itself is version 6.9.2, which is several years old. New version numbers on the packages now reflect updates to the media player, converter, etc.
The "DivX" brand is distinct from "DIVX", which is an obsolete video rental system developed by Circuit City Stores that used custom DVD-like discs and players. The winking emoticon in the early "DivX ;-)" codec name was a tongue-in-cheek reference to the DIVX system. Although not created by them, the DivX company adopted the name of the popular DivX ;-) codec. The company dropped the smiley and released DivX 4.0, which was actually the first DivX version, trademarking the word, DivX.
DivX ;-) (not DivX) 3.11 Alpha and later 3.xx versions refer to a hacked version of the Microsoft MPEG-4 Version 3 video codec (not to be confused with MPEG-4 Part 3) from Windows Media Tools 4 codecs. The video codec, which was actually not MPEG-4 compliant, was extracted around 1998 by French hacker Jerome Rota (also known as Gej) at Montpellier. The Microsoft codec originally required that the compressed output be put in an ASF file. It was altered to allow other containers such as Audio Video Interleave (AVI). Rota hacked the Microsoft codec because newer versions of the Windows Media Player would not play his video portfolio and résumé that were encoded with it. Instead of re-encoding his portfolio, Rota and German hacker Max Morice decided to reverse engineer the codec, which "took about a week".
In early 2000, Jordan Greenhall recruited Rota to form a company (originally called DivXNetworks, Inc., renamed to DivX, Inc. in 2005) to develop a MPEG-4 codec, from scratch, that would still be backward-compatible with the Microsoft MPEG-4 Version 3 format. This effort resulted first in the release of the "OpenDivX" codec and source code on 15 January 2001. OpenDivX was hosted as an open-source project on the Project Mayo web site hosted at projectmayo.com (the name comes from "mayonnaise", because, according to Rota, DivX and mayonnaise are both "French and very hard to make."). The company's internal developers and some external developers worked jointly on OpenDivX for the next several months, but the project eventually stagnated.
In early 2001, DivX employee "Sparky" wrote a new and improved version of the codec's encoding algorithm known as "encore2". This code was included in the OpenDivX public source repository for a brief time but then was abruptly removed. The explanation from DivX at the time was that "the community really wants a Winamp, not a Linux." It was at this point that the project forked. That summer, Rota left the French Riviera and moved to San Diego "with nothing but a pack of cigarettes" where he and Greenhall founded what would eventually become DivX, Inc.
DivX took the encore2 code and developed it into DivX 4.0, initially released in July 2001. Other developers who had participated in OpenDivX took encore2 and started a new project—Xvid—that started with the same encoding core. DivX, Inc. has since continued to develop the DivX codec, releasing DivX 5.0 in March 2002. By the release of version 5.2.1 on 8 September 2004, the DivX codec was substantially feature-complete. Changes since then have tended to focus on speed, and encouraging wider hardware player support, while the company has also focused its time on the formats and next-generation codecs.
In February 2011, DivX was acquired by Rovi Corporation, upon completion of its acquisition of Sonic Solutions. In 2014, Blackstone Group and Parallax Capital acquired DivX from Rovi for $75 million. On January 5, 2015, it was announced that IPTV company NeuLion would acquire DivX for $62.5 million. In February 2018, a deal was finalized to sell certain DivX assets, intellectual property, and subsidiaries from NeuLion, Inc. to Fortress Investment Group.