Which javascript templating framework for mobile first designs?

The reason I want to use this is because this is within a corporate environment. It makes sense to use something that requires very little setup and is already supported by modern browsers. I also don't have access to database or JSON strings so everything must be stored locally and versioned through something like Git.

I'd love to go full-blown with a MVC framework but at this point it's overkill and I'm still a complete newb. This will serve as a prototype, mostly a proof of concept when it's finished. My main needs would be for templating common elements, like header, footer, content areas, etc.

If I can do something fast enough, I might be able to use this as a way to convince the overlords of the company to ditch trying to go with a CMS like CQ5, Teamsite, or another Java based system.