good news: after a month of hunting a) spammers and b) server admins, the needed wiki extensions to prevent and delete wiki spam finally got installed and the database updated so that those extensions can work. (Done in the english wiki, the others will follow.)
This means the wiki is editable again :-)
It also means we now have an easy way to block spam, and can mass-delete existing spam pages.
As every good news, there's also a bit of bad news - the database update cleared all cache, which means the wiki is terribly slow at the moment.
BTW: If I accidently delete something that was not spam while doing the mass deletion, please tell me ;-)
For those who are interested in details: - the Nuke and AbuseFilter extensions were installed - I just added the first spam filter - let's see how it works out (and tell me if it accidently produces false positives ) - I just started to delete all the spam. If someone has admin permissions on the english wiki and wants to help, head over to https://en.opensuse.org/Special:Nuke and enter something like %1_8% as page title search term. It uses MySQL LIKE syntax, as a regex the example means .*1.8.* (the "all pages" list will give you more spam page titles if you sort by creation date) - If you are interested in helping with AbuseFilter rules, see https://www.mediawiki.org/wiki/Manual:Combating_spam/AbuseFilter_examples and https://www.mediawiki.org/wiki/Extension:AbuseFilter#Documentation_and_manag... for documentation.
If you reply to this mail, please answer only to one list. Cross-posting the announcement is enough ;-)
 Funnily I was the first victim of the spam filter ;-)
I didn't exclude the 'delete' action on the first attemp. When I tried to delete pages with spammy title, this was denied because the page title matched the spam filter ;-)
Lesson learned: I need to exclude the 'delete' action from the filter ;-)