At 18F, starting with open source means that the public can go look at their work on Federal Election Commission data or read the unit’s open source policy or track how a project on Freedom of Information Act requests is going.
I use GitHub to follow what’s happening with Project Open Data, one of the explicit outcomes of the open data executive order the president issued last year. It’s messy, sometimes uncomfortable, and puts mistakes out the open, but it’s absolutely fascinating. To say that this is all a bit different than the development process for other government websites, policies, or software applications would be to engage in a gross understatement.