I'm happy to see this reach beta version, it's a great step in the right direction. Grunt is too generic as a tool and we've all seen Gruntfiles reach enormous lengths, to a point when it's really hard to figure out what is processing what.

One thing that has room for improvement though is the syntax, which in my opinion doesn't reveal the intention behind some methods and is a bit too coupled with the implementation. What does `makeTree('lib')` mean? If it's taking a folder and its files then why not rename it to something like `broccoli.requireFolder('lib')`? Also another thing that might improve usability would be chaining compilers instead of calling them directly with the tree as parameter.

These are just minor things anyway, I'm sure the library will improve over time. Congrats joliss, great fan of your work!