Pure CSS is owned by the YUI (Yahoo User Interface) team. It is open source, and at the time of writing, still early in the development process, the current version is 0.2.0. What Pure CSS aims to do is bring a set of CSS classes to aid in the development of grid, and responsive grid websites, provide a number of classes to easily create common user interface elements (menus and forms), and produce a set of styles to create nice looking buttons, tables and more.