To clarify,
Developer
Bitovi
JMVC 3.3 is built on CanJS. So you'll have features like live-binding, etc. However, it comes with aliases as well.
So:
$.Controller === can.Control //behind the scenes.
DoneJS === JMVC 4.0 and has no aliases. JMVC 3.3 is the stopgap between the two, to make migrations a bit easier and bring new functionality to the older API.
Developer
Bitovi