Linker.php splits off some of the internal bits from Skin.php. Linker's functions are used primarily for page content: links, embedded images, table of contents. Links are also used in the skin. For the moment, Skin is a descendent class of Linker. In the future, it should probably be further split so that every other bit of the wiki doesn't have to go loading up Skin to get at it. Linker contains methods to create internal, external or image links and implements page existence detection. To use this class, use $wgUser->getSkin().
