On Tuesday, Steve Ballmer is expected to make public a report and database that looks at revenue and spending across federal, state, and local governments. The effort comes from Ballmer's new startup, called USAFacts, that he and a team of professionals built secretly over the past three years.

The database could be one of the most ambitious nonpartisan efforts to investigate what the government does with tax dollars, according to The New York Times' Andrew Ross Sorkin. Users can look up questions like how much revenue do airports take in or how much does the government spend on diagnosed depression. Ballmer has spent more than $10 million on the project, between grants and direct funding, the Times reported.

"I would like citizens to be able to use this to form intelligent opinions," Ballmer told the Times. "People can disagree about what to do--I'm not going to tell people what to do."

After the former CEO of Microsoft got the idea, he hired a team of researchers in Seattle and created a grant to the University of Pennsylvania to assist his staff with the data collection. The billionaire entrepreneur wants to open up the project to individuals and companies so they can build on top of the research and pull out customized reports.