Stephen Downes

I don't know whether ePub is a revolution, but it is something new and it is increasingly important. ePub is the format used to publish eBooks, and is used by Apple's iBooks, Barnes & Noble's Nook, the Sony Reader, iRex's Digital Reader, and iRiver's Story, among others. Wikipedia has an article on ePub here. If you want to read ePub documents in your browser, you can use a Firefox extension. What makes ePub distinct from other content formats is that it creates a flow of content that can exist over several pages, and which displays more or less text per page depending on page size and text viewing area. Other than that, there's a packaging format, which defines things like table of contents and (optionally) digital rights management. If you want to create your own ePub documents, you can use the free and open source Sigil document authoring tool.