Open Source Business Intelligence/DWH solutions
I have been working with Pentaho for about a year now.

Pentaho is a full Open Source suite for Business Intelligence.

It's strenght is that it relies on independently managed project :


Pentaho Data Integration (Kettle) ->ETL 
Pentaho Report Designer (PRD) -> Report designer 
Mondrian -> R-OLAP cube
and much more..


You can use them as a whole (Pentaho BI Server) or apart.

Why would I recommend it ? The community is really active and provide plugins on a weekly basis. A group of community members provided a framework for building interactive dashboard with a click&amp;go ui.

It is database independant. If you have some free time just take a look at it.

I did a research before using Pentaho, I did test IceCube and Palo even JasperSoft but Pentaho was from far better according to my needs.