Boks is one of my most successful apps and this is probably not only because of its usefulness, but also because it is free, too. I released it more than 2 years ago and it is still heavily downloaded.
The CSS community is really active and fast-moving. When I wrote Boks, Blueprint CSS was one of the most watched and forked project on GitHub which is mostly why I chose to base my UI and logic on it (it still is at the top, by the way). But with today's CSS3 hype and because of the ever-growing list of CSS frameworks (not going to list them here) I started receiving lots of feature requests.
At first I thought I could wait and handle them later, but I quickly realized it would need a lot of time, and I definitively didn't have it in my hands (or at least not for this project). The idea to OpenSource it seemed obvious and I've been slow doing so, but here it is. If anyone's willing to take a look at what I wrote and fix or improve it, do it! Don't forget that this has been written a while back and I wouldn't re-write it this way (think Robotlegs); I know the code will look crappy to some but hey, we all learn and evolve, right?
I've licensed Boks' source under GNU GPL v3 in order for it to remain OpenSource, but if you have other suggestions, just tell me.