github or else?

is it possible to take a view into the wiki sourcecode on github or somewhere else? would even like to make some issues…

OpenStreetMap Wiki’s underlying software is called MediaWiki.
It has a very active community.
Do note that if you make some fixes, it could take a while until they get into a stable release and only then have OSM Wiki updated.

as far as I know, it is already a hacked version of mediawiki, thats why Iam asking for the code.

But even if it is not, what plugins are installed? How can I get the raw data? etc. etc.

Plugins and other customizations of the wiki installation are visible here: https://wiki.openstreetmap.org/wiki/Special:Version

The content of the wiki used to be published regularly as a dump on http://dump.wiki.openstreetmap.org/, but this is no longer available. As such, there is no easy way to obtain the wiki content or store a local backup. Unfortunately, comments about this have so far been ignored. :frowning: