FilePro

filePro is a proprietary DBMS and RAD system developed by fptech, Inc. Originally sold as Profile, by Radio Shack in the late 1970s, the system was later renamed and has changed hands several times. Data is stored in B-tree files, and all records are of fixed length. This is not a true relational database, because it does not satisfy Codd's 12 laws. It does, however, allow for rapid prototyping of curses-like screens, and add-on products are available for ODBC interoperability, CGI-like functionality, and even a form of SQL peculiar to filePro.

Furthermore, there is a small, dedicated community of developers, and there is a mailing list based at http://mailman.celestial.com/mailman/listinfo/filepro-list