Add an easy way to link to other pages without having to type the full URL, and you've got a radical improvement on a wiki.

Perhaps you could use double-bracket links like GitHub wikis use, so this would be a [[ubpdk|link to another document]].

Why markdown everywhere, don't we have better markup languages?

Do we? Recently looked into that and it didn't seem like there is something clear-cut superior, sadly...

Asciidoc seems superior to me at least.

IIRC Dokuwiki wasn't too bad either.

Standard Markdown used to lack some important constructs, again IIRC.

Really? What are they?

Markdown seems perfect for this case where the markup is the rendered content.

Very cool, but what's the issue with mobile? I use Swype and it only inputs the first letter of each word.

What is the stack?

It's almost pure front-end using Firebase + Firepad (https://firepad.io/). The editor uses CodeMirror (http://codemirror.net/) and custom highlighting rules. The backend (what little of it exists) is in Flask :)

Very cool!