Database Engines
- SQLite (Embedded database system library, which is mostly SQL92 compliant. License: none, it is public domain.) (cvs) (ml)
- Berkeley DB (Embedded database system library. License: BSD-style with source requirement)
- PostgreSQL (Mostly SQL92 compliant RDBMS. License: BSD-style) (cvs) (ml) (GBorg portal for PostgreSQL related projects) (Autodoc tool to create XML/HTML/Dot documentation from a database structure) (General Bits pgsql-general-ml news) (my2pg Perl script to convert a MySQL database dump into a PostgreSQL database. my2pg is included with the PostgreSQL package.)
- MySQL (Mostly SQL92 compliant RDBMS) (ml) (forums)
- Firebird (Mostly SQL92 compliant RDBMS based on Interbase code. License: InterBase Public License) (cvs) (ml)
- SAP DB (Mostly SQL92 compliant RDBMS) (ml)
- SHSQL (C based embedded SQL database library, which stores data in ASCII text files. License: GPL)
- picoSQL (Mostly SQL92 compliant RDBMS)
- PBL (Embedded database library for C/C++ projects. License: LGPL) (source)
- WB (C library for a disk based sorted associative-array, with an optional interface to the SCM Scheme implementation)
- QDBM (Embedded database library. License: GPL)
- LEAP (Educational RDBMS project. Inactive project.) (cvs) (ml)