Seems the old Theora video codec, an early attempt at a freely-licensable algorithm unencumbered by patent restrictions, has largely fallen into disuse <https://www.theregister.com/2023/11/02/theora_video_codec_deprecation/>. In other words, it has served its purpose, and the patent minefields that used to plague video encoding have (to mix metaphors) been effectively defanged. I remember when the Xiph.org foundation came out with the Vorbis audio codec as a free alternative to MP3, back when Fraunhofer was still vigorously enforcing its patents on the latter. Xiph also came up with a multimedia container format called “Ogg”, which could handle both audio and video. But given it was, at least in the early years, only used for audio, quite a lot of people assumed that a “.ogg” file was audio-only. So the video files had to have the “.ogv” file extension (I think there were some “.oga” files to indicate that they were audio-only). The name “Theora” comes from Theora Jones, one of the principal characters in the old “Max Headroom” TV series. “Vorbis” is from a character in Terry Pratchett’s “Discworld” novels. I thought “Ogg” also came from those novels, but Wikipedia says no.