We built an HTML5/CSS/jQuery website and visualized the data using a free map service, CartoDB. We initially crunched the publicly available campaign finance data using Excel. At the end of the day we were happy to have a functioning product ready to demo. You can see the product of our work: version 1.0 of OpenDSJ.
Since the hackathon we have added over 38,000 lines of code, changed from Excel to R, and further updated the data and maps. Looking forward to v2.0, we will be making the map larger, incorporating the use of Google Maps (instead of CartoDB), and adding a slide bar to the map to show snapshots in the campaign timeline.