It was a dark and mild night as Sunlight welcomed a frighteningly awesome group of friends and supporters to our Halloween open house yesterday. In what is now an annual tradition, Sunlight turned on the black lights (literally) and created what may be the spookiest place in Washington, D.C. outside of the Exorcist steps.

Guests enjoyed refreshments, Simpsons’ Tree House of Horror episodes, making Bumble tweet and much more ghoulish fun.

Stopping by the @SunFoundation Open House? Tweet with #bumbletweet to make our monster sing! Also works for people who wish they were here.

— Boo Lannon (@BobLannon) October 30, 2013

Thanks to all who attended and celebrated Halloween with us. Whether it’s hosting fun events like this one, developing websites such as the newly re-launched OpenCongress.org, or growing a community of API users, it would not be possible without your support. Please consider making a donation to the Sunlight Foundation today. You can also keep up-to-date with our news and events on Twitter, Facebook, or via email.

See all photos from the open house on Flickr.

* Apologies to Charles Schulz.