I also think we're agreed that we want to use free, open-source, non-proprietary software. This narrows things down considerably.
I'm willing to shelve the idea of leaving open an obvious pathway to getting the data into 'semantic web' triple form. I think this means we don't need to consider or discuss this aspect of things any further. I've also shelved the detailed proposal I was working on, as I think it would only be a distraction from getting started.
Technologies considered so far are: MediaWiki, Waliki, Tiki and Xwiki. If anyone else has found anything suitable, obviously we can consider that. I've haven't after a fair bit of research.
Of these, I think there's general agreement of those expressing an opinion that MediaWiki is too Byzantine. Waliki is in early development and doesn't have a DBMS, using github as a back-end instead, so I'd strongly prefer not to use that. The other two seem viable.
Chris, via one of our round robin emails (I assume it's OK to publish this):
I agree with this, and think Tiki offers us the best chance of getting started quickly and using features 'out of the box' while affording us the ability to customise functionality as we choose. Php has apparently been substantially improved as a programming language in recent years, and is definitely more widely supported by hosting providers etc so allows us more option there should we need them.
From playing around with it, XWiki looks very powerful, but possibly a bit intimidating for us as administrators to get set up; there are a lot of options available. PHP vs. Java probably shouldn't massively inform our decisions, except in that it might be slightly simpler to get PHP apps set up with a web-hosting company. However, I don't foresee this being a massive issue either way. I will say that I have more experience with Java than PHP, so that does make me lean in its direction a little
So I'd like to propose that we go with Tiki as our best option given that we want to get things rolling quickly.
I am in the process of getting a server set up which we can use as a live system under the labourroots.uk domain. Is Windows acceptable as an OS? Tiki will run fine on it. I'm not trying to steamroller this through, just to get things moving forward after a brief (apparent) hiatus.
One issue we need to consider is how comments/talk pages are to work. In wikipedia, talk pages are an unstructured nightmare. Somewhat better formats are available as extensions to MediaWiki, and in other more recent wiki software. However, especially in the context at least of using a wiki for policy development, we should certainly be thinking about how this is actually going to work, and whether talk pages are likely to descend into long-winded slanging-matches.
Tiki allows forums to be used to discuss Wiki pages, which is better than the unstructured nightmare of MediaWiki talk pages, but not sure it offers the kind of tight integration between edits and discussion I'd ultimately like to see - but not sure any other Wiki software does either so that is a wash. Ditto creating tighter and more easily interrogable tracking of exactly which contributions were made by whom.
I'm going to go ahead with setting up a Tiki installation for now, but obviously any objections, suggestions, etc can be made and addressed here.