Oracle, Microstrategy, Microsoft, and IBM are on the leading edge in the latest Gartner Magic Quadrant for Business Intelligence Platforms report.
Other companies in the leaders Quadrant include Information Builders, QlikTech, SAS, and SAP. Tableau and Tibco Spotfire are in the Challengers Quadrant.
Gartner Summary:
In 2011, business users continued to exert significant influence over BI decisions, often choosing data discovery products in addition to/as alternatives to traditional BI tools. An avalanche of new use cases, content types and interaction models expands the scope for tomorrow's BI platforms.
Here is the report
Magic Quadrant for Business Intelligence Platforms report (reprint thanks to SAS).
See also SAS in Leaders quadrant for business intelligence platforms