[fleitz]

The only portable GUI code that I've ever seen work somewhat reliably is HTML/CSS.

Everything else either implements a 3rd GUI, Swing, et al, or looks weird on a few of the platforms, GTK.

Oddly enough the best cross-platform lib I've seen, Qt, is written in C++.

C certainly isn't the be all and end all, however, it's far more portable, reusable, and linkable than C#.

[TIHan]

From a platform perspective, Qt is good for all the desktop environments, but for mobile, .NET/Xamarin is the way to go.

From a language perspective, why in the world would you want GUI code in C or C++? Both languages make it very easy to shoot your foot off and have no idea what happened. However, C can be very elegant if used for the right reasons. C# is safer, but also not perfect. That's where F# comes in. :)

[fleitz]

I actually had a super hard time with F# and XAML, this was back in F# 1.0/1.1 days.

While not strictly C, ObjC/UIKit is a helluva language for doing GUIs.

I actually don't like GUIs in C++/Java, or C# because it's far too restrictive and you spend all your time making the class hierarchy happy and typing boiler plate rather than getting stuff done.

ObjC is a beautiful mix of scriptyness and performance / low memory utilization. If ObjC is too slow, C is right there, and if it's too complicated for C add in a little C++. My typical mix is usually about 90-95% ObjC, 5-10% C, and 1% C++.

I love that if you know an object supports a method you can just cast to id and call it. If an object is missing a method, you just add it. If a base class is stupid, you override it.

Java/C# are total pieces of crap in this regard, although C# is far better for having extension methods.

[reboog711]

Too bad you missed out on Flash / Flex. At one point it was absolutely brilliant.