Microsoft SQL Server is a relational database management system (RDBMS) developed by Microsoft. It runs on Windows systems and uses Transact-SQL as the query language.

Microsoft SQL Server release history:

* 1993 - SQL Server 4.21 for Windows NT

* 1995 - SQL Server 6.0, codenamed SQL95

* 1996 - SQL Server 6.5, codenamed Hydra

* 1999 - SQL Server 7.0, codenamed Sphinx

* 1999 - SQL Server 7.0 OLAP, codenamed Plato

* 2000 - SQL Server 2000 32-bit, codenamed Shiloh (version 8.0)

* 2003 - SQL Server 2000 64-bit, codenamed Liberty

* 2005 - SQL Server 2005, codenamed Yukon (version 9.0)

* 2005 - SQL Server 2005 Express Edition, restricted free version