Pure is a responsive layouts Framework. It has css for typography, grids, forms, buttons, tables and navigation.
Markup used is very simple and the whole framework is pretty lightweight (5.7KB minified and gzipped). Pure is very much Modular. The styles with each module can be used seperately.
The Yahoo! CDN supports combo handling, so you can combo your requests and get a single CSS file back. Here’s an example of a combo URL that only includes CSS for Base, Grids, and Forms:
The YUI Skin Builder is a very nice tool to create custom pure css themes. With a single click, the Skin Builder is able to generate all the CSS needed for forms, buttons, layouts, tabs etc.
Pure is an open-source project under the BSD License. Check out the code repo on GitHub.