What kinds of Software do you create in D.

[MGW]

I've been writing in D all the time since 2012. Various 
applications for processing large CSV files, converting between 
different formats, etc.
Main library QtE5 (now QtE56) - working with Qt-5 (Qt-6) on Win, 
Linux and OSX. Does not require Qt MOC. Does not have any 
external dependencies. Can use QtDesigner to create forms. A 
typical compilation for a GUI application is: dmd guitest.d 
qte56.d -release
The biggest GUI application on QtE5 is ek87.exe - working in 
dozens of cities, testing nondestructive testing for oil and gas 
specialists.

Intermediate demonstration for Windows 64 + Qt-6:
https://github.com/MGWL/QtE5/tree/master/demo_Qt6