iWork for iCloud beta now opens to all registered users with an Apple ID. The beta contains full access to in-browser versions of Apple’s iWork software suite, including Pages, Numbers, and Keynote. iWork for iCloud was first introduced at Worldwide Developers Conference last June and sent invited to only registered developers then adding some non-developer users.
It will work well if you plan to use Safari, Internet Explorer or Chrome on either Mac or Windows computer. Earlier than this month, iCloud beta received an iOS 7-inspired makeover and some have iOS 6 look. The official iWork for iCloud will be ready this fall. You can access to iCloud website and check out to see what iWork looks like anytime.
Source: iCloud beta