From my archives of items to post:
According to an article in the Library Journal earlier this year, there is a new digital format that will challenge the PDF. The CDF, or Computable Document Format, is a new standard that was released on July 21st by Wolfram Research, and it enables users to “interact with online documents, input their own data, and generate results, live.”
Comparatively, CDF allows interactivity and motion in a document, whereas in PDF, documents are static and unchangeable. CDF files behave more like apps than documents, and they allow users to make their own “knowledge apps”, of which more than 7,000 have already been created by researchers, educators, and students using an early version of CDF. CDF documents can currently be created using Mathematica 8 and distributed for free using the Wolfram CDF Player, which is required to view the CDF document. Currently, there is a beta CDF in an e-textbook currently on the market: Briggs/Cochran Calculus, and many other publishers are showing great interest in the technology. The CDF technology is on its way to changing the way that online documents and e-textbooks allow users to access, and interact with, information.
It will be interesting to see if this format can stand up to other developments, such as those around Epub3.