- UNIX and C.
- Android and Java
- Windows and .NET/C++
- JME feature phones
- iOS and Objective-C/Swift
Or to taking it down to memory lane,
- Burroughs and ESPOL/NEWP
- IBM RISC systems, IBM zOS and PL/8
- IBM 400 and PL/S
- Lilith and Modula-2
- Native Oberon and Oberon
- UCSD and Pascal
- Lisa, Mac OS and Object Pascal
- Lisp Machines
- Smalltalk workstations
- Xerox Star and Mesa
- SpinOS and Modula-3
- .... (plenty more to list)
Not true. .NET is VB, C#, which are completely different from C++, and you can write a Windows application in almost any language imaginable.
Sure you can write a Windows application in anything else, but be prepared for a 2nd class experience, writing FFI bindings on your own for the Windows API, without access to the tools provided by Visual Studio.
The alternatives to the languages I listed, don't enjoy the same support to 100% of plaform APIs, and respective SDK tooling.
Going outside the eco-system means manually writting FFI bindings, not being able to use the GUI designers if available, lack of debugging and profiling support at the same level as the platform tools.