WatiNCssSelectorExtensions is a project mainly written in JAVASCRIPT and C#, it's free.
A set of extensions for selecting elements in the WatiN test framework using CSS Selectors.
Initial release as a nuget.
rake
Downloads available at https://github.com/haf/WatiNCssSelectorExtensions/downloads
Place nuget file from downloads in local folder and use nuget package manager to get it (this is valid advice until there's a descriptor out there for it!)