ssqlfs uses a defined file/directory structure to generate an SQL database which corresponds to that file/directory structure. Along with support for one-to-many tables, ssqlfs includes support for representing many-to-many tables. Ideally, the filesystem would be interconvertible with an SQL database, but at this point the functions for generating a file/directory structure from the SQL database remain to be thoroughly tested.
The Objex Project (like the GNU Project) aims to develop a complete operating system composed of free and open source software. In contrast to the GNU Project, it aims to build a modern system that brings together all the recent advances in computer science, instead of a Unix-like system. "A complete system" means that it will include the kernel, a full suite of developers tools, user utilities, and a graphical user interface. It is based on OSKit, a framework and a set of utilities, drivers, and program code intended for operating system creation.
fbsql aims to ease the use of Firebird and Interbase databases by providing clean client libraries for different languages. The raw Firebird/Interbase API is very awkward and hard to work with, while fbsql is easy and straightforward, like the sqlite and MySQL APIs. Currently C and Lisp are supported. fbsql uses IBPP, a C++ Interbase/Firebird API for its implementation. It's basically just a thin wrapper around IBPP to make it accessible in C.