Tumbler is a D-Bus service for applications to request thumbnails for various URI schemes and MIME types. It is an implementation of the thumbnail management D-Bus specification described on http://live.gnome.org/ThumbnailerSpec written in an object-oriented fashion using GLib and GObject. Its modular architecture makes it very flexible and useful in many situations. It provides plugin interfaces for extending the URI schemes and MIME types for which thumbnails can be generated as well as for replacing the storage backend that is used to store the thumbnails on disk. Tumbler's functionality can also be extended via specialized thumbnailer services implemented in accordance to the thumbnail management D-Bus specification.