And (not included yet) is the hackathon group I started last year: startups.philadelphia.groupomatic.com/
Mostly microsoft focused meetings but a little ruby also.
I'm in Baltimore, so it's a little tough for me to get to DC events. Our best event is the SocialDevCamp East , which is basically a Barcamp-style event.
In April is jsconf, though the speakers and location are TBD.
It's also a community driven open source project with multiple code-sprints per month!
--Igal Koshevoy, Calagator Developer