Pentaho has not made it onto the quadrant diagram yet (I suppose because they have not crossed the $20M revenue threshold), but earns its own paragraph in the accompanying commentary:
Pentaho, after just four years in existence, has put together a comprehensive open-source BI platform that includes data integration and data mining capabilities. In 2008, Pentaho was noticeably more aggressive, openly competing against traditional BI platform vendors. Like Jaspersoft, Pentaho is affordable and also offers a subscription-based model that avoids an initial large payment for the software license. Some of the significant features Pentaho introduced in 2008 include an automatic table designer that analyzes relational schemas and data patterns, performs a cost-benefit analysis of aggregation at different levels, and generates and populates those aggregate tables. Despite a handful of large customers, Pentaho reference survey respondents more frequently indicated that they had more departmental deployments (versus enterprisewide) and smaller data volumes compared with the other vendors.
Nice that the aggregate table designer gets a call-out. It's very important in helping Mondrian scale to enterprise-scale data warehouses. (And besides, it was a lot of work to write!)
The report calls out the quality of Pentaho's customer support:
This was in evidence in the MQ reference survey, as both Jaspersoft and particularly Pentaho scored strongly on the customer support question — higher than any of the megavendors.