HTML5 Canvas, 2nd Edition

Theora + Vorbis = .ogg

Theora is an open source, free video codec developed by Xiph.org. Vorbis is a free, open source audio codec that is used in conjunction with Theora. Both Theora and Vorbis are stored in an .ogg file. Ogg files have the broadest support among traditional web browsers but, unfortunately, not on handheld devices. These files can also be represented by .ogv (video) and .oga (audio). Many commercial companies (for example, Apple) have balked at using Theora/Vorbis because they are unsure about whether somewhere, someplace, someone might own a patent that covers part of the technology, and thus they might get sued for using it.

Note

Sometimes technology companies get hit with what is known as a submarine patent. This was a patent tactic—available up until 1995 in the United States—that allowed a filer to delay the publication of a patent. Because patents were only enforceable for 17 years, if someone filed one but delayed the publication, he could wait years (even decades) until someone else came up with the same idea and then hit that person with a lawsuit.