The development team of the Perian plug-in for QuickTime has announced today that it will no longer be making future versions of the plug-in.
The Perian project began over six years ago, and the plug-in has been a simple and straightforward way to add extensive media support to OS X without juggling multiple media players.
Commonly referred to as the Swiss Army Knife for QuickTime, the Perian plug-in included a number of the codecs required to view most video formats available via the Web and was the answer for many who were trying to find a way to view obscure, outdated video files. It often was used to overcome the limited default codec support in Apple's QuickTime player.
Unfortunately, the developers have decided to move on to other projects, and in a posting on the Perian Web site, said they will be halting support for the software after 90 days from its final release. The source code will then be posted to an open-source community (Google Code or GitHub), where others can try maintaining it if they so choose. There will be no official support for Perian in Apple's upcoming OS X 10.8 Mountain Lion, but unless Apple changes the way the program is allowed to interface with QuickTime then it should continue to function, though there are no guarantees.
If you are looking for media support options in OS X, besides Perian there are a few other programs that will let you view obscure and unsupported media formats. One of the most common is the VideoLAN Client (VLC) media player, and another is MPlayer OS X Extended (be sure to get the binary codec pack for this player). Additionally, the Perian developers are promoting NicePlayer as an alternative.
Perian will be missed, but there should be enough alternatives available to fill the void.