LibCSS is a CSS parser and selection engine, written in C. It aims to parse the forward compatible CSS grammar. It was developed as part of the NetSurf project and is available for use by other software under the MIT licence. For further details, see the readme.
You can browse the source code via the online interface. Alternatively, you can check it out of SVN:
$ svn co svn://svn.netsurf-browser.org/trunk/libcss
LibCSS is licensed under the MIT Licence.
If you would like to help develop LibCSS, or have questions about the library, please join the NetSurf developer mailing list.