Uploading documents to iWork.com requires a copy of the iWork '09 software suite and an Apple ID. Viewing, commenting, and downloading require only a web browser and an invitation to view the document.
Apple announced that after July 31, 2012, users will be no longer able to publish new documents to iWork.com from any iWork application. Documents stored on iWork.com will not be available to download or view after the shut down date. Instead, users can use iCloud to share documents between their computers (running OS X Mountain Lion) and their iOS devices.