Firebird is a relational SQL database offering many ANSI SQL-92 features that runs on Linux, Windows, and a variety of Unix platforms. Firebird offers excellent concurrency, high performance, and powerful language support for stored procedures and triggers. It has been used in production systems, under a variety of names (the most famous being "InterBase") since 1981.
In 2000, Borland decided to release InterBase 6.0 as Open Source. Firebird is an independent development, beginning with these sources, driven by an Open Source Community and funded by the Firebird Foundation.
The Firebird Foundation collects money to help the Firebird project go along and fund important parts of the development.