Compass was an internal project to develop a business dashboard. It was a difficult project because they had wanted two features: complete historical month-end data and adhoc searching all of that history. Of course, this would be available to external clients, too, so there would be strict security needs.
And on a budget, of course.
After initial attempts using an existing Oracle server, I was able to make a case for a very successful switch to Postgres for the reporting data.
The server component is a pretty standard Java application with REST-style APIs to serve the Flex frontend.
In all, there was a small cost for the database server and my time, but it was tiny compared to the very expensive products large organizations typically buy.