Source : Free On-Line Dictionary of Computing

SQL Server
     
         (Note capitalised)
     
        1. Sybase {Adaptive Server Enterprise}.
     
        2. {Microsoft SQL Server}.
     
        (2003-07-02)

SQL server
     
         (Note not capitalised) Any {database management
        system} (DBMS) that can respond to queries from {clients}
        formatted in the {SQL} language.
     
        Two popular examples are {Microsoft SQL Server} and {Sybase
        SQL Server}.
     
        (1997-12-07)