GML is a sub-project of the gAnimus project. While I was developing gAnimus, I needed to develop a file format to describe the saved characters, and the data that would be used to create them. Thus began the GML project; a set of XML schema files that describe all of the data used in the GURPS game.
I've made my first release of the GML schema files. Get them while they're hot from the download section. Have a look, tell me what you think, let me know about any immediately obvious flaws. Comments, Comments, Comments! Tell me what you want to see.