Need a way to create and extend custom post types, content types, taxonomies, users, media, or comments in your WordPress install? Then you might want to check out the Pods Framework. It’s open source under GPL, to boot.
The Pods Framework puts you, the developer, in charge. It’s a plugin that contains an interface and PHP codebase that allows you to base content types off of their own custom tables designed around the needs of each content type. Built with love by the members of the WordPress community, for the WordPress community, it’s free as in speech for perpetuity.