b2evolution is a powerful blog tool you can install on your own website. It includes all the features of traditional blog tools, and extends them with evolved features such as file & photo management, advanced skinning, multiple blogs support as well as detailed user permissions... Not to mention third party plug-ins!
One of the main differentiating features of b2evolution is its ability to manage multiple blogs under a single installation. Features in current releases include: community-wide spam filters, in which many b2evolution sites aggregate and "tag" spammer IPs into a central blacklist for the benefit of all b2evolution blogs; a fully skinnable interface; localization into a dozen language packs; and a fully exposed API for plugin developers to add new functionality. Several popular plugins have been developed for b2evolution. These include text format extensions enabling Textile, Auto-P, Greymatter, BB code, Texturize, LaTeX, and graphic smilies. Also, plugins which facilitates full integration with third party tools such as Gallery 2, YouTube and digg are available.