Originally you say it was a kind of kiosk operating system that ran a Web browser with Google apps deeply integrated to enable things like a little local file storage.

Some years ago, they enabled you to access a real local Linux operating system, and install and run arbitrary things.

I think but don't know that local Linux gives me a container or windows subsystem for Linux vibe.

It's sufficient to use a chrome book as a local dev machine, and I think googlers do that daily.

It was a weird kinda locked down linux with some google proprietary stuff last time I touched it, about 3 years ago.