I compiled my first Arduino code (Marlin for my new 3D printer) on Microsoft’s Visual Studio Code. I found it a lot easier to use than the Arduino software. Not sure if it would run under Wine for you Linux folks, but I am sure you already have your favorite compiler.
It’s actually running the exact same compiler underneath the VSCode IDE, and it’s using platformio to drive the compiler.
What’s weirder is that it runs natively on Linux.
Weirder still? It’s open source under the very permissive MIT license. I understand that MS has non-open-source parts that fit into VSCode, but I think that everything you need for Arduino under platformio under VSCode is open source.
(I still use platformio from the command line, but that’s my own oddity.)