Comment by btilly

Amazing. Your comment is wrong on every respect.

Whether you are entitled to write fanfic is not a straightforward case. As https://en.wikipedia.org/wiki/Legal_issues_with_fan_fiction documents, some authors allow it, some don't, and fanfic sites pay close attention to who does. The fact that you can write Star Wars fanfic is not entitled under law, it is entitled by implicit or explicit permission from the copyright holder. Star Wars is OK. Pern? Not so much.

Oh, and sometimes you can both write and sell fanfic legally, no matter what the copyright holder thinks. For a famous example, Bored of the Rings is legal because it is marked as parody.

Moving on to open source, you are even more squarely wrong. The definition of open source, as found at https://opensource.org/osd-annotated, in item #6 says that commercial use must be allowed. In other words anyone is free to try to make money off of that open source project they forked as long as they follow the license.

In fact the term "open source" was invented as part of a marketing campaign to encourage the use of free software for commercial purposes. Far from "you can't make money from this", the whole intent was to encourage people to try to make money from it. And seeing that you could, to encourage businesses to make more of it! (This marketing campaign was successful, which is why you both have heard of the term some 20 years later, and everyone uses open source software.)

Now the license may restrict what business models are feasible. For example you can't edit GPL software then sell it as proprietary. But that is a MAY, not a MUST. As an example, selling relabeled BSD software commercially is both explicitly allowed and occasionally encouraged.