SQL:2008 is a language. MS SQL Server 2005 is an implementation, which includes some extensions to the SQL language (notably "T-SQL", use at that link). To me,

SQL:2008 is a language. MS SQL Server 2005 is an implementation, which includes some extensions to the SQL language (notably "T-SQL", use at that link). To me, at least, it's much more surprising to find that the official SQL language is Turing-complete than that someone's implemented proprietary extensions that make it so. Your mileage may vary.