Looking for Unconventional Forum Software

What you're proposing sounds a lot like http://barbelith.com/. You may want to look at the setup of their site (which runs on proprietary software, IIRC) for ideas.

I also want an invite to this site! The http://www.ilxor.com/ILX code is open source, and while broken down into boards has an "all site" page that combines them into one. Perhaps some general topic headings as boards, then everyone can look at the all site page? It doesn't have tagging, though, and the archives are mainly just by date or search. It's on the Ask A Question model, but that's mostly for form.

Two thoughts, one helpful and one not. For an infinitely expanding forum base the most appropriate method would be to use the tags as the organizing criteria. Instead of a menu or list of forums, the user would click on tags to get to the forums (or discussion threads) that apply to that (or those) tag(s). Effectively this is putting the search first: the user will click on the search results they want to return the forums of their choice. Secondly, this really sounds like putting the cart before the horse. Google "premature optimization" to learn a little bit about tackling all conceivable problems before you have them. In short, get the users and discussions going first, then worry about the problems that ensue. It'll ultimately be a smaller task.

I've thought about this before and it occurred to me then that since the aim is to foster free and open discussion of literary subjects the best solution would be something generic but powerful. Start with a few strong categories but rely on tagging to draw out the relationship between specific discussions. This way you don't need a billion and three categories and you aren't dictating what or how your users will construct their dialog. You are merely facilitating; by providing a forum (as in public space) for conversation and tools for self regulation you let the users do the heavy lifting. Not unlike the way Metafilter appears to have evolved. Something like http://www.joomla.org/ has the power and relative ease of use for what you need.

In short, get the users and discussions going first, then worry about the problems that ensue. Best advice in the thread.

I'd tend to agree about premature optimization, but I've also seen how the limitations of a technology platform influence both discourse and community. I think the op is right to consider whether starting out with ordinary forum software will leave him with something that never feels all that different from a regular forum.

I'll surf Barbelith, Joomla, and ILX a little later, but many thanks in advance. Grod, it won't be quite as chatty/freeform as I've made you think (I'm sparing you all lots of extra details!). It'll be more pragmatic, but more loosely pragmatic than ask.metafilter. rhizome, what you're describing is the sort of tagged forum software I described (and noted the shortcomings of) in my OP. As for putting cart before horse, what I'm doing - selecting software to provide the best framework - is hardly "tackling all conceivable problems before you have them". It's a fundamental decision that ought to be skillfully made. In any case, I'm not really looking to examine my basic assumptions. I'm pretty comfortable with them....I'm just looking for some software advice. :) To those asking about invites, this forum will be private, and thus not competing with anyone, including Metafilter, but it'd still feel sleazy for me to recruit people from this community to join mine (though needless to say it wouldn't be either/or in any case). I may start a thread on Metafilter Talk to discuss the ethics of that.

http://www.getvanilla.com/ might be worth checking out for you

crap i'm a doofus, just read the part that you already liked vanilla