Isn’t a “wiki” a web site that allows people to post and edit content? If that’s true, how is Wikileaks actually a “wiki”? Do people post and edit content on that site, or is it just a data dump of classified material?
The Straight Dope is a web site that allows people to post and edit content; its not a wiki. And a wiki can still be a wiki without being publically editable by everyone - it’s just a type of software, not a philosophy. There are people who use wiki software to create websites with a small number of editors.
That said - no, I don’t think WikiLeaks contains any wiki software. At least, looking at it, I can’t see anything which looks like wiki software.
So, Assange is guilty of a grammar crime! I knew we can nail him with something. 
A “wiki” merely refers to the software they use to run the web site.
Wikipedia runs on Mediawiki software. It is free for anyone to use as long as you accept their license agreement (Creative Commons license).
WikiLeaks, at least originally, ran on the Mediawiki platform. Hence the “wiki” part. Not sure if that has changed lately.
While wikis tend to be open for anyone to edit that is by no means necessary. I run a wiki that, while open to the public to read, is restricted in who is allowed to edit it.
ETA: I should note that wiki software is modifiable and some wiki sites do not look a whole lot like a wiki site.
Wikileaks used to be an actual wiki using the same software as wikipedia. It was definitely a real wiki back when it leaked Palin’s emails as wikileaks.org in '08, at least.
That’s not grammar, that’s semantics.
That’s semantic. 
It looks to me like it still uses wiki software, but I would not call it a wiki. To quote from, well, Wikipedia (who gets it from the guy who invented wiki): “A wiki invites all users to edit any page or to create new pages within the wiki Web site, using only a plain-vanilla Web browser without any extra add-ons.”
IIRC, they abandoned the wiki-model a year or so ago (before the first material from Manning was leaked). Originally they’d hoped to just let anyone leak whatever on the site and then have users add commentary, but it was to hard to separate the crap from legitimate material.
The idea of Hillary Clinton sitting around on her home PC engaging in an edit war over the “diplomatic cables page” with Julian Assange is pretty amusing though
Amusing, yes, but inaccurate. Surely you don’t think she would abase herself, so. That’s what she has State Department minions for.