For something trivial and cross platform: Tcl with Tk or Python with wxpython. Java with Swing does still exist and works too. It's harder (IMO) to "scale" a

For something trivial and cross platform: Tcl with Tk or Python with wxpython. Java with Swing does still exist and works too. It's harder (IMO) to "scale" a Tcl/Tk or wxpython project though as there aren't great built-in patterns and especially with wxpython, the API is a bit clunk and boilerplate heavy. For a bigger project that you don't need to be cross-platform, you can still make a Windows Forms C# project in Visual Studio. It still works pretty well even, although Visual Studio seems to get slower and farther from this use case each year.