Doom9.org is a prominent online platform dedicated to digital video and audio processing, primarily focusing on the subjects of DVD, Blu-ray, and digital media technologies. With a rich history dating back to 1998, the website has provided users with a comprehensive range of guides, articles, and forums, making it an invaluable resource for enthusiasts and professionals alike. Doom9.org boasts extensive coverage of video codecs, authoring tools, decrypting techniques, and cutting-edge software, allowing users to stay updated with the latest advancements in the world of multimedia. Its active community of knowledgeable contributors further ensures that Doom9.org remains a go-to destination for those seeking knowledge and assistance in the realm of digital media.

Due to the concentration of forum members who have technical backgrounds, there have been various software projects developed and maintained by forum members. These include:en.wikipedia.orgDoom9 is also known for being the main discussion forum for many major video encoding tools, such as x264, AviSynth and MeGUI .

The earliest information on how to find title and volume keys was also first revealed on Doom9 forums, by other users.en.wikipedia.orgDoom9 gained notoriety as a result of its involvement in the AACS encryption key controversy. The utility BackupHDDVD was first posted by a Doom9 poster using the alias muslix64.