The DC municipal government actually has a Github organization (https://github.com/dcgov) and has been attempting to pilot open source development (http://open.dc.gov/open-source-guidelines/) throughout the city. I helped write that document, which was inspired by/borrowed from 18F policy. Take up has so far been limited, though some agencies have been using Github Pages.

Also, if you're interested in issues like that, you'd probably really enjoy joining the http://codefordc.org/ community! I've only attended one Meetup, but it was the most ridiculously welcoming and well-run tech meetup I've ever attended!

I doubt it directly applies to DC government at all. But they have their own program: http://open.dc.gov/

I think a lot of progressive cities are already way ahead of the federal government on this one.