Adobe is almost certainly one: https://helpx.adobe.com/creative-suite/kb/microsoft-visual-c-runtime-error.html https://helpx.adobe.com/creative-suite/kb/micros

Adobe is almost certainly one: https://helpx.adobe.com/creative-suite/kb/microsoft-visual-c-runtime-error.html https://helpx.adobe.com/creative-suite/kb/microsoft-visual-c... There's probably quite a few internal-only users of Visual C++ too. EDIT: Well, they're a high-profile user of Visual C++, I have no idea if they require C99 support but they ship a Mac version so it's possible.