In the documentation for the new SOAP Service we make use of a relatively new feature in the Socialtext Wiki markup: the ability to include one page within another. If there's some chunk of content that is or will be useful in more than one place (for example the impersonation description page in the soap documentation) we "extraclude" the content to its own page and then include it in multiple pages.
In hypertext tools this functionality is usually called Transclusion. Content is stored in one place but used multiple times in multiple places to create multiple documents or narratives.
At Socialtext we use the term quite loosely (because it's useful to us that way) to refer to having stuff over there that gets used over here. When we update it over there we see the changes over here. Including one or more pages inside another page is a form of transclusion, and so is including the contents of an Atom or RSS feed. Transclusion, in whatever form you get it, allows the dynamic composition of complex documents from smaller pieces.
I started playing with transclusion when I implemented it for Blueoxen's experimental Purplewiki platform. In Purplewiki, individual paragraphs and list items can be transcluded at a granular level meaning an author can pick and choose small pieces from another large document. Socialtext is not there yet, but we're making steps in that direction, choosing simple changes with immediate value. Someday soon, I hope we'll be able to do dual-ended transclusion, where editing is possible on both ends of the transclusion link.
The SOAP Service and our forthcoming REST API allow a similar kind of transclusion: Content stored in a Socialtext wiki can be presented in other systems including web portals, desktop applications and specialized interfaces.
It's easy to look at transclusion as a geeky hack--it's pretty cool to wiggle some content over here and have some stuff over there change--but that's not really the point. Transclusion is one of several tools (like Wikis themselves) that enhance our ability to make use of the information and understandings emerging in a group's communication and narrative.
--Chris Dent
