I’m surprised this hasn’t been mentioned: Can I read the code? This applies to everything open source, including languages. If you open up the codebase and go

I’m surprised this hasn’t been mentioned: Can I read the code? This applies to everything open source, including languages. If you open up the codebase and go “wtf” that’s a problem. If you open up the codebase and go “I don’t understand this, but it looks clean and with some effort I could understand this” that’s gold. This is especially true for libraries, you get a sense for the right size and right amount of complexity in dependencies.