[License] join-plugin

[Jérémy Costes]

Hello,

I would like to use join-plugin for jenkins but I do not found license.

What license is used ?
In https://github.com/jenkinsci/join-plugin some files have MIT header
but not all.
Thus there is a possibility that join-plugin is not under open-source
license.
Moreover I do not found jenkins agreement which implies jenkins plugins
are under MIT by default.

Do you have more information about join-plugin license please ?

Regards