quiddity, 25/10/2014 20:26:
We don't have HTML preview, which might be interesting. Surely it's possible to whip up a userscript for it, if anyone would actually find it massively useful. (Or, we can just leave the browser's own Web Developer bar open to see the HTML. ctrl-f is our friend.)
Are you sure we don't? Well, last time I used livepreview was probably 2007 or so, but it's still in preferences. https://www.mediawiki.org/wiki/special:search/livepreview also not very useful.
Nemo