No, this is not an advertisement for PurpleWiki (although PurpleWiki does support Transclusions). This is a wakeup call. Transclusions already exist and have existed for a long time. No, I’m not talking about Project Xanadu. I’m talking about the World Wide Web and spreadsheets, among others. (IDZ)
First things first. What’s a Transclusion? A transclusion is a link where the content of the link is displayed inline. For example: (IE0)
is a link. This: (IE2)
is the content of that link displayed inline. Which, of course, is example number one. Images on the Web are transclusions. When I include a URL in <img> tags, the content of that URL is displayed. (IE4)
We use Transclusions all the time in spreadsheets. When I write =E27 in a cell, the spreadsheet displays the content of cell E27. (IE5)
Transclusions are useful, and they’re ubiquitous, but not necessarily as “transclusions.” They’re not yet part of a shared conceptual framework for collaborative tools. Once we explicitly acknowledge their existence and their utility, we can think about implementing them across different applications in an interoperable way. (IE6)