Movable Type is an open-source blogging platform and content management system distributed under the GPL. It used to be under a more restrictive, non-free licence (but with source), but has become open-source later. Movable Type has many skins and plug-ins available on the Web. It keeps an HTML cache of its pages on the hard-disk in case they are read without being modified, which may cause some problems with world-editable files.