Firebird RDBMS offers ANSI SQL features & runs on Linux, Windows & several Unix platforms. Features excellent concurrency & performance & powerful stored procedure & trigger language.
More information and downloads at https://firebirdsql.org/, issue tracker is https://github.com/FirebirdSQL/firebird/issues
This project is the development of an open source fully emulated Darkfall Online Server and reverse engineering the proprietary game engine that DFO uses, the SF3D engine as well as its source code.