Github ToS and Open Source

Fri Mar 3 15:57:47 UTC 2017

On Fri, 03 Mar 2017 16:35:31 +0100, Xen wrote:
>Colin Law schreef op 03-03-2017 15:24:
>> Can anyone explain the significance of this in words that the
>> relatively uninitiated can understand?
>> https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm  
>
>What it appears to say is that Github hosted projects can only be
>forked on Github, all projects must allow to be forked, and
>attribution-style licenses are forbidden.

Wouldn't this be a discrepancy? If something is GPL'ed and provided at
Github, why should somebody forking it, provide it via Github, too?
This would be an addition to the GPL. The GPL allows to fork a project
and to distribute it, without the restriction of being forced to
distribute it using Github. Right?