I believe they have started explicitly targeting C99 support in more recent versions in order to make it easier to port C code developed against gcc or clang.

Here's an older article - http://blogs.msdn.com/b/vcblog/archive/2013/07/19/c99-librar...

(I've seen more recent ones, but I can't find an example to hand)

Given that the video was already a bit old, this is the latest official statement I could find, from 29 Apr 2015.

http://blogs.msdn.com/b/vcblog/archive/2015/04/29/c-11-14-17...

"Q. What about the C99 Core Language, or the C11 Core Language and Standard Library?

A. Our top priority is C++ conformance. We've implemented the C99 Standard Library because C++11 incorporated it by reference. C++ (up to the current Working Paper) hasn't incorporated the C99 Core Language in its entirety (only a handful of features, listed above), nor is it ever likely to. It may incorporate the C11 Standard Library at some point in the future, but that hasn't happened yet.

In VS 2013, the compiler team implemented some C99 Core Language features in C mode (e.g. designated initializers, see MSDN for the full list), in order to support some popular libraries. "

No they were pretty clear that it is only what is required by C++ standard, and some high profile customers.

There was a C9 interview about it, need to search for it.

Could not find the interview video, but this was another one I remembered have watched:

https://channel9.msdn.com/Events/Visual-Studio/Launch-2013/V...

Starting at 00:18:40, note the "not an intent to conform to C99/C11".

FFMpeg was one of the customers

Out of curiosity, who are MSVCs high profile customers?

They didn't mentioned on the interview.

If I recall correctly it was at a Visual Studio event last year, on those floor interviews they publish with the teams on C9.

Adobe is almost certainly one:

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.

One of them was FFMpeg, from the video I digged out.

When I was in that situation (maybe ten years ago), we ran gcc on Aix, HP-UX, Solaris, Linux, Tru64, SGI, and maybe a couple of others. Then of course there was Windows, which used the Microsoft compiler. But using only two compilers made the ten or so platforms easier to deal with. (There still was a bunch of code that was "#ifdef SGI/#else/#endif", and similarly for other platforms, but at least the compilers behaved the same.)

We had to use the vendor compilers, so no fun.

This was the only time period I used C instead of C++ at work.

However I do confess, the situation for C++ support was even worse, so although I am not fan of C, the decision made sense from business point of view.

How long ago was your experience? Was gcc an option at that time? Or did management require you to use the vendor compiler?

What we did was, we used the vendor compilers to compile gcc for a platform (or maybe used gcc to cross-compile itself, I forget). Then we used that gcc to compile gcc for that platform. Then we used the new gcc to compile gcc for that platform, and made sure that it was the same as the previous gcc. This wasn't easy - we had one guy that this is pretty much all he did for months. But it got us to a place where we were free from the vendor compilers.

> How long ago was your experience?

It was back in the first .com wave, so 1999 - 2002.

> Was gcc an option at that time? Or did management require you to use the vendor compiler?

Customers did. Our software needed to integrate with their existing toolchains.

At least for our customers gcc was not a serious compiler, given the license and being that funny open source thingy.