Servo is one of a hundred initiatives that they have. They have been developing the Rust Language itself, and all the tooling around it. They are trying to kill PDF plugins with PDF.js. They are trying to kill closed source video codecs with Dalaa. They have been trying to improve online collaboration, multimedia, 3D, and a zillion other things.
They also help with web standards, documentation, legal battles, and advocacy.
They also help with web standards, documentation, legal battles, and advocacy.
http://www.mozillalabs.com/en-US/projects/