Using Qt 4 vs Qt 5 to develop application for Windows and OS X? [closed]

Question

I am considering using Qt to port a standalone Windows application to OS X and possibly Linux. I have never used Qt before. I do not know if I should work with Qt 4 or Qt 5.

I would be interested to get the feedback of developers of fairly large applications using Qt 4 and 5. What are the pros/cons for each version?

More info about the project:

The application is a high end tool for digital photography: real time HDR, Tone Mapping, etc, of large photos at 96-bits per pixel.

The application is currently using the following technologies:

• UI code : C#, C++/CLI, .NET 2.0 WinForm
• Core algorithms: C++, OpenMP, SSE

I plan to use the Qt framework to redevelop the UI code. I have the following constraints:

• Supported OS: Windows XP, Vista, 7 and 8; OS X; (Linux)
• Two builds: 32 and 64-bit
• Application must be able to run on VMs (with little or no OpenGL support)
• Execution speed / real time aspects are essential
• Main development environment: Visual Studio on Windows 7 64-bit

Thanks!

Answer 1

Based just on your platform constraints you probably want to use Qt 5. Windows 7 64-bit is a tier 1 platform in Qt 5. Windows 8 isn't even a tier 2 platform in Qt 4. Qt 5 has better support for High DPI displays (important to Mac users with Retina displays).

• Qt 4 Supported Platforms
• Qt 5 Supported Platforms

Answer 2

If you're trying to avoid OpenGL then Qt 5 isn't going to be a good fit as they moved towards using it as a dependency for QML widgets and the scene graph. That's not to say you can't use it at all, but it's certainly something to consider if you've got an aversion to OpenGL.

Qt 4.8 is perfectly mature, the code base is pretty well covered at this stage, so might be a better fit as the drawing libraries aren't coupled onto OpenGL.