Verdict
This is a very capable suite of BI, reporting, and data mining tools with sophisticated functionality, and will address the needs of many organisations.
Pentaho BI Suite Community Edition (CE) includes ETL, OLAP, metadata, data mining, reporting and dashboards. This is a very broad capability and forms the basis for the commercial offering provided by Pentaho.
A variety of open source solutions are brought together to deliver the functionality including Weka for data mining, Kettle for data integration, Mondrian for OLAP and several others to address reporting, BI, dashboards, OLAP analytics and big data.
The Pentaho BI platform provides the environment for building BI solutions and includes authentication, a rules engine and web services. It includes a solution engine that facilitates the integration of reporting, analysis, dashboards and data mining. Pentaho BI server supports web based report management, application integration and workflow.
The Pentaho Report Designer, Reporting Engine and Reporting SDK support the creation of relational and analytical reports with many output formats and data sources.
If you want a version with support, training and consulting, as well as a few more bells and whistles then Pentaho provide such services and product.