driveway is an explorative project for developing pure CSS masonry layouts. It is developed using stylus. You may have come here from the blog post I wrote about pure CSS masonry layouts. If that's the case and you want the exact code I used in that post(with vendor prefixing), you'll be best served looking in the dist folder for driveway.blog.css and driveway.blog.min.css. Alternatively, use bower to pull in the repo.