[neltnerb]

Definitely, it's always used GCC under the hood, and also just been the IDE.

Arduino (the original AVR boards anyway) have always relied on GCC, and not just that but the entire open source chain that already existed for AVR-GCC. I'm sure they contribute back (I guess "sure" is an exaggeration), but it worked pretty darn well already.

Arduino, for me, replaced emacs for an IDE. The main reasons I use it are because I don't need to write a makefile, and the integrated serial port. Those are good enough features that I still use the IDE even though I haven't touched a real Arduino in a decade or more. But I work alone and don't usually have more than a few thousand lines of code so it's not too complex to manage.

[1718627440]

That tracks with my experience, since I don't prefer the IDE, because I need a build system that generates unique IDs and conditionally compiles stuff and handles debug flags. Also it needs to be reproducible and run unattended. In addition a build system is way faster. Arduino almost spends half of the build time on reanalyzing the project files to find out, what it actually needs to do and then it creates build artifacts in a random location. That's all problems you don't have with a proper build system, so the build system ends up way faster. I think Arduino also doesn't support parallel compilation.