Seth Keen

Web pages as applications concept: (quote from web page) 'In the case of the new iWork files, changing the file extension to .zip and expanding the archive reveals the as-expected XML document and plist files (for the document and its formatting) as well as a little PDF surprise — a preview version of the file. What this means for you is that you can send an iWork file to a friend or co-worker and regardless of their operating system choice or installed software base, they can “view” your document by unzipping it and opening the PDF.'