In order to reduce complexity on xwiki.org instance and make it easier to manage the playground wiki itself (which used to be located on https://playground.xwiki.org which now redirect to the new location) we decided to move it to its own dedicated instance on https://www.xwikiplayground.org. hosted by XWiki SAS Cloud. If you're interested you can find the discussion about this move on the forum.
For those who don't know it, the playground wiki is a sandbox in which you can test the wiki the way you want (but with limitations in terms of rights), and where the changes are automatically wiped up every day. The main difference with the previous instance for now is that you cannot use your xwiki.org account to edit on playground anymore, you will need to register an account (which is going to be wiped every day like the rest of the wiki).
We might also decide to open up new features on playground that used to be impossible for security reason (Velocity script, etc.) when it was a subwiki of the xwiki.org instance. This still needs to be discussed.
