It's entwined, and has been for nearly a decade. MS licensed Dinkumware's STL back in the mid-90s (and I know almost nothing about the early history). Around 20

It's entwined, and has been for nearly a decade. MS licensed Dinkumware's STL back in the mid-90s (and I know almost nothing about the early history). Around 2005, MS was doing things like adding security features to the STL, but not really sustained development. In Jan 2007, I joined the VC team and since then I've spent almost all of my time on the STL (with one brief detour). For a long time, I fixed bugs, dealt with MS-specific stuff (DLLs, calling conventions), reported compiler bugs, that sort of stuff, with PJP delivering new features (starting with TR1 in 2008 SP1). I review all STL checkins, preventing bugs from happening in the first place. In the last few years, I've tackled larger overhauls and started implementing larger features. For example, in this release I rewrote the TR1-era <functional> implementation (keeping only std::function's skeleton), implementing C++17 invoke() as a side effect. Other MS devs have contributed STL bugfixes in this release, and a couple of features (e.g. uncaught_exceptions() and sized deallocation), so it's not just the PJP and STL show.