Derived from Burning Wheel, but winding up fairly different in many details.
Luke in an interview posted to RPGGeek.com:
You also worked on Mouse Guard, which uses your Burning Wheel system. What about it appealed to you in regards to adapting Burning Wheel to it?
My friend Clinton R Nixon showed me the first issue of the comic in 2005 at ICON in Stonybrook, NY. In that issue one of the characters says, "It's not what you fight, but what you fight for." That is essentially what Burning Wheel is about. Clinton tried to work with the creator to design a game for him, but that fell through. I took a shot at it purely as a design experiment -- to see if I could strip Burning Wheel down to its core and keep it intact. We ended up with a rather different, unique game in its own right. I like it very much.
RPGGeek Page: http://rpggeek.com/rpg/799/mouse-guard