I've used the "first" (?) version of Sourcegraph and now this new one, and I have to say I'm a huge fan. I'm learning Go in the evenings and I was struggling to grasp some of the concepts in Go and how to use the Gorilla package. Personally, I learn better after I skim the API, look at an example and rinse/repeat as needed. For me, Sourcegraph is a great way to help speed up that process of finding that one example that helps make whatever it is "click".<p>I've been using their Chrome Extension because it injects their stuff right onto Github pages. Now all they need to do is make one for Firefox, so I can go back to Firefox.<p>Disclaimer: I meet Quinn at GopherCon and we talked about Sourcegraph. I loved the idea then, and I still do now.