GitHub is not open source.

It is a hosted server for a piece of free software (git) although obviously with a huge amount of proprietary software bolted on top.

Thank you!

Can someone please explain how is the dual license work? Should there be any differentiation in the product, for example, community edition vs enterprise edition?

Also, how is the sponsorship work? For example, OBS Studio has Facebook and Twitch as sponsors.

Dual license can be on different products, e.g. community edition and then you have extra binaries or plugins which come with a commercial non-open license.

But it can also be by use case. MongoDB's has extra requirements for those who run services (database-as-a-service) and thus who compete against MongoDB, the company. https://en.wikipedia.org/wiki/MongoDB#Licensing

Sponsorship is hoping companies rely on your software enough to open their money pockets. Or to have a strategic interest, e.g. by keeping something open/free that a competitor charges money for. https://letsencrypt.org/sponsors/

Thank you!

Will people pay for a license if there's no differentiation? (In HN we read a lot of stories where even donate button is not working well)

Also, will people pay for a commercial add-on when the product itself is free? (open core model)

> Will people pay for a license if there's no differentiation?

That is really a separate issue. If there is no differentiation from its competitors, then it may not be used at all.

People aren't generally the customers of dual-licensed software; usually companies that ship proprietary software are the customers. The typical model for dual-licensing is to allow the code to be used in an open source project for free but charge for the code to be used in a proprietary project.