Fancypants_generators is a project mainly written in RUBY and JAVASCRIPT, it's free.
v0.3 960gs
Just a quick heads up, since you're here- I just opened up this project and haven't gotten to do a lot of testing so there are surely still bugs and issues. It's changing everyday, so I wouldn't put it into production yet unless you were planning on doing work and contributing back.
This version includes conformance to a 12 column 960gs, and Sass based inheritance for font sizes.
Feel free to fork and contribute, or post bugs and issues.
FancyPants is a web app theme written in Haml and Sass, geared towards Ruby on Rails apps.