Just to clarify for others that might be confused about the "about a decade": To the best of my knowledge it started in 2009. No criticism of the understatement, only to save others the look-up.
> Initial commit
> @brson - committed Mar 29, 2012 - 0 parents commit 4825529 - Showing 1 changed file with 1,522 additions and 0 deletions.
https://github.com/jdm/servo/commit/48255297b8958fa559d11704...
http://venge.net/graydon/talks/intro-talk-2.pdf
The Wikipedia article about Rust says:
"Mozilla began sponsoring the project in 2009 as a part of the ongoing development of an experimental browser engine called Servo [..]"