ESP8266: Developing code for commercial use in accordance with the licence

Hiya, does anyone have any experience with writing code on ESP8266 for commercial use? I'm concerned with licensing issues and legality of use.

I'm wondering what IDE/firmware/libraries/itd. will allow the code and batch to be sold legally, so that the developer and customer don't have problems later. Not that I have anything against free software licenses, I just prefer to rest easy and don't want someone to sue me/demand damages/expect to make the code public/whatever you can think of there.

Greetings and thanks for safe solutions .

You need to know the basics of the Open Source licensing group, because without that, the conversation will be about nothing.
You definitely can't lump them together, but there are a multitude of materials, and a moderately smart develo chimpanzee can distinguish between them.