I usually go straight to https://www.xwiki.org/xwiki/bin/view/Blog/Releases to read about new releases, but since a couple of days that keeps going in 504 - double checked from my mobile so this is not an issue with my local network.
But other pages at XWiki.org do work, even the blog ones, i.e.: https://www.xwiki.org/xwiki/bin/view/Main/News