Universal Subtitle Format

Universal Subtitle Format (USF) was a CoreCodec project to create a clean, documented, powerful and easy to use subtitle file format. It is based on XML for some of the following reasons: flexibility, unicode support, a hierarchical system, and ease of administration.

USF subtitles are usually used in Matroska Containers, meaning that it will probably be usable in html5 since they plan on using Matroska Containers internally as video format.

VSFilter, and VLC media player (starting with the 0.9.0 release) can extract the subtitle text, timing information and very restricted formatting.

Titlevision subtitling system supports USF format as its own internal format, so it handles both proper reading and writing of it, they have also extended support so that it now handles open and closed subtitles and comments, on every subtitle.

The format has come under criticism, especially from the fansub community [1], because compared to the format it aims to replace, Advanced Substation Alpha (which is based on comma-separated values), it is more verbose and far harder for software to read, write and manipulate. It is also much harder to edit "by hand" in text editors such as notepad. For these reasons, as well as the lack of a generic cross-platform parsing/rasterizing library and mature editing programs that natively support it, the format has not gained wide acceptance.