On the one hand, this framework's front page almost undersells the biggest feature it has, which is that I believe it can function as an actual Erlang node. You can use this to join a Go system to your Erlang cluster directly. This is pretty impressive because that's nontrivial functionality.
On the other hand... this is a pure an example of a transliteration as an idiomatic port as I can think of. There is simply no need, in pure Go at least, to blindly copy every last detail of the Erlang implementation for gen_server for general usage, and more than you should copy every last such thing for Javascript or Python or any other language. If you are joining to an Erlang node and working in the Erlang ecosystem, you have no real choice, but if you aren't doing that, this library is going to add a lot of friction to a lot of things in Go, all over the place.
It's a very niche thing. If you need it it's probably worth all the money, but I'd pay to not get it put into a greenfield Go project.
On the other hand... this is a pure an example of a transliteration as an idiomatic port as I can think of. There is simply no need, in pure Go at least, to blindly copy every last detail of the Erlang implementation for gen_server for general usage, and more than you should copy every last such thing for Javascript or Python or any other language. If you are joining to an Erlang node and working in the Erlang ecosystem, you have no real choice, but if you aren't doing that, this library is going to add a lot of friction to a lot of things in Go, all over the place.
It's a very niche thing. If you need it it's probably worth all the money, but I'd pay to not get it put into a greenfield Go project.