The Skin manager tool allows site administrators to install and manage skins in a Sakai instance. Skins are uploaded in the portal as .zip archives that contain graphics and style sheets. The tool displays all the skins in use throughout the Sakai instance and indicates which sites use a particular skin. Skins may be revised by uploading a new archive and it is possible to revert to earlier versions of a skin. This strongly simplifies the skin installation process: no longer access to the file system of the sakai instance is needed.