I could see this being more like code blocks instead of actual software engineering. He probably found the different language modules and stuck them all in, and then did the equivalent of changes to a config file.

He did not "program" 6 languages. Even if he was a super genius and spoke 6 languages, there's physically not enough time for Anakin to have typed the entire vocabulary and grammar of 1 language, much less 6.

Imo, his "programming 6 languages" was plugging in 6 hardware language modules and running a command to load them.

Does not require access to source code though. Could still be closed source..
What does wookirpedia say.. Apparently the 3po protocol droid series was manufactured by a company called cybot galactica. That page confirms that c3po was cobbled together from scrap. I don't see anything about the cybot company running open source software though

He’s a slave boy in a scrap yard on some backwater shithole of a planet. Sue him

The first step down a dark path if he's not careful.

There is no copyright if you lack the star destroyers to enforce it. Or enough money to pay the headhunters.