Bricklin's WikiCalc: Much much more than just a mashup of wikis and spreadsheets | Between the Lines | ZDNet.com: "Drawing from one of the names ? VisiCalc ? that gave birth to the PC industry, electronic spreadsheet co-inventor Dan Bricklin has gone public with an alpha version and his plans to release WikiCalc ? an open source browser-based solution that takes some of the most powerful features of spreadsheets (eg: the ability to format anything including text and calculated data into a tabular layout), some of the most endearing features of Wikis (ie: their simple markup language and instant ability to collaborate on Web-based documents), and marries them not only to each other, but also in very behind-the-scenes-fashion to advanced Web page formatting techniques that involve tables, HTML templates, and cascading style sheets."
Also see Dan Bricklin's essay About wikiCalc 0.1