From their contributing page:
https://remix.run/docs/en/dev/contributing
> "We need you to "sign" a contributor license agreement (CLA) first that assigns us ownership so we are able to include it in this software. We don't yet have a CLA, but we are working on it and we will be able to accept your contributions as soon as we do."
Apparently, requiring a CLA isn't as uncommon as I initially thought, but I'm still curious why some projects require this but others do not. What about their business model / licensing choices necessitate a CLA?