The Wikipedia Test Wiki is not:
- A place to put content or anything meaningful;
- An area to play with administrator's tools. If you are looking for that, see Wikipedia:Requests/Tools;
- A place where you can test AutoWikiBrowser (AWB) before being given permission to use it;
- Where nonsense articles will stick;
- A web host, wiki host, or files (video, image etc.) host;
- A test for new projects or language versions of Wikipedia, see Incubator and Wikispore instead;
- Where you can get away with everything;
- Where libel will be tolerated;
- A community.
...at least from what I've heard.
The Wikipedia Test Wiki is for developers to test their code without breaking all of Wikimedia and blowing up the world.
The Wikipedia Test Wiki may also be used in a classroom environment for teaching basic wiki editing to avoid the great confusion resulting from creating pages and breaking a regular project, although this may not always be desirable because of the occasional difference between the test interface and a typical Wikimedia project interface.