Depends on what you're looking for
The operational term these days is probably "CMS" -- content management system. The question then becomes: from whence the content?
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Your basic user-comment boards include Slash, PHP-Nuke, Scoop, and related products (of which zIWT is one -- though it's not going to perform well under high demand -- we can clobber it with a mere 400+ registered users, due to single-threading).
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Wikis are more aimed at documentation, typically within a defined technical community, or company, than world-at-large uses. It takes some grokking to get the concept. While I'm strongly enamored of TWiki for what I use it for, I'm not sure I'd toss it at a bunch of woodcarvers. Though I might pitch it as a secondary option.
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At the high end, CMS is an article + feedback system. Take a look at Linux Journal (PHP-Nuke IIRC), Slashdot, and Kuro5hin. Here we're largely in full-feedback mode -- threaded discussion. CMS can be a full website management solution, or just a user feedback area. Solidify what it is they're looking for.
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I'm all but positive that 'BBS' (dialup connections to a message board) is not what they're looking for.