Google has released Material Design Lite, which is just a few CSS and JavaScript files that enable deb designers to easily tap the looks and feel of Material Design.

I have just begun to poke around with it, but it seems like it's going to be a great tool for developers who are making web apps. It's just CSS and JS, so I thought "hey, I could use this for some elements on BirchTree," but I doubt that's going to happen.