An OpenWeb is a web-based environment that is open for readers to edit.  It's meaningful in contrast to the traditional closed web, where it takes web developers, web masters, communications professionals, editors, or otherwise complicated FTP uploads, HTML coding, and chmod work about which most MereMortals have no clue.

Wiki is the quintessential OpenWeb.  However, there are other things that also make the web open, like bloggers.

By the way, ever notice how your colleagues have a hard time with the word "wiki?"