Since 2005 I've been working in the software infrastructure department in Bloomberg. Bloomberg doesn't give a lot away about its internal technology or what we do with it, but occasionally things are made publically available. There is an increasing presence on github, most notably with our version of the STL and some basic libraries following our coding standards. More specifically to my own work there's a video after the fold of a talk by a colleague at jsconf 2011 about the internal development environment we built a few years ago for the developers building the Bloomberg terminal: