iCloud now allows Pages, Keynote, and Numbers editing on Windows or OSX for free.
Try it out at
iCloud Beta allows for Office Productivity into Apple’s Cloud using Windows or OSX. These include Pages, Numbers, and Keynote. Users can upload Microsoft Word, Microsoft Excel, and Microsoft Powerpoint directly into a browser to edit save or update! Please find high level beta images outlining the features below.
Pages for iCloud
Numbers for iCloud
Keynote for iCloud