+1 for "Sharepoint is a wiki", even though that wasn't the main topic of the article.<p>I've known for ages some things that Sharepoint <i>does</i>, but I've never been able to wrap my head around what it <i>is</i> (what's the unifying theme, what's the boundary between Sharepoint and other systems it integrates with, etc).<p>People and websites tend to call it a "platform for leveraging organisational collaboration" or something equally content-free.  Wikipedia calls it "a collection of products and software elements that includes, among a growing selection of components, ..."<p>Saying "it's a big clever wiki with bells on" seems like a better starting point.