From http://docs.http-prompt.com/en/latest/contributor-guide.html : > Fork is a term invented by GitHub. No, it is not. Also, do I get royalties for my contributions to this open source project? Since you're literally selling other people a gated license to the code I contribute, I'm wondering how this works from a legal perspective.
Doing that without a Contributors License Agreement seems at the very least iffy. (AGPL + commercial isn't exactly unusual, but normally there is a CLA involved)
That said, the specific arrangement in this case may be a bit strange. There's a "commercial end-user license agreement", which I'm pretty sure is not possible–unless they are the author of all the code in question, in which case they can make up as many licenses as they want.