I was browsing through the datasets on the website, and datasets like "Tax Year 2007--" caught my attention. At first I thought it might be Census data. However, if you look at the "About" tag for that dataset it says it's from the IRS. I also noticed that you can filter by agency through the menu on the left of this page I was using to browse the datasets. It would be nice to have some sort of grid view for just the contributing agencies that provided stats about their contributions.
Is this a comprehensive list of contributing agencies, and is there a way to view all of them at once other than the small list view?