Apple's iWork for iCloud took another step towards coming out of beta by opening up to all Apple ID holders, including Windows users. Previously, the public beta was available only if you used Apple gear to access the website.
iWork for iCloud beta now open to Windows users
The web-based versions of Pages, Numbers, and Keynote are designed to work cross platform, just like Microsoft's online versions of Word, Excel, and PowerPoint.
The platform-native versions of the iWork apps are available for free when you buy a new Mac, iPhone, iPad, or iPod touch. The online versions are free to use even if you don't already own the versions for OS X or iOS.
You can try out the iWork for iCloud public betas by logging into your iCloud account.