Precompiling Haml-like templates into Underscore templates

I can't stand the traditional HTML syntax. Haml, Slim, Jade are much more readable and concise.

I'm using Backbone which does template rendering clientside. I don't want to burden users forcing them to download. An additional templating library will not increase product value for users. Instead, i would like to precompile templates serverside.

Backbone depends on Underscore and underscore has its own templating engine.

So the question is: how do i precompile templates from any indentation-based language (Haml, Slim, Jade, etc) into Underscore templates? Preferably with Gulp.