SQL Server Analysis Services, an OLAP server bundled with SQL Server by Microsoft since version 7.0
SSAS (SQL Server Analysis Services) is an OLAP server bundled with SQL Server by Microsoft since SQL Server 7.0. It is not available separately. The query language used by SSAS is MDX (Multidimensional Expressions); queries can be issued through a web service API called XML/A (XML for Analysis).
Originally purhcased from a third party (Panorama) SSAS is now developed by Microsoft.