The most popular online office applications include Google Docs, Microsoft Web Apps and Zoho. Both Google Docs and Zoho focus on providing an online office application service. They're not an adjunct to an offline product, which is the business model for many other free online office applications.
As starting from 2012 December GoogleApps stops to be a free solution we propose you Microsoft Online Services.
What is Office 365?
Office 365 is a cloud-based service hosted by Microsoft. It brings together the familiar Microsoft Office desktop applications with cloud-based business email, shared calendars, instant messaging (IM), video conferencing, and file sharing. It's designed to work with the Office you already know so you can get things done faster from virtually anywhere. It provides enterprise-grade tools for a predictable monthly cost and no upfront infrastructure investments, backed by robust security and a 99.9% uptime guarantee. It's the easiest way to work together.
While still too new for it to be deemed "most popular," Office 365 offers a compelling online suite of enterprise-level applications including Exchange Online for email, SharePoint Online for collaboration and Lync Online for unified communications. Most subscriptions to Office 365 include the aforementioned Office Web Apps. Pricing starts for as little as $6 per person, per month.
Whether you are looking for an application to take care of occasional computing needs while on the road, or you're looking for a free online alternative to a paid offline program, you'll find plenty to like in cloud-based small business software.
Microsoft was a late starter in the world of free online office applications, but it is impossible to ignore. With a Windows Live ID you can sign up for free access to cut-down versions of Excel, Word, PowerPoint and OneNote online.
You don't have to own Microsoft Office, but if you do you can easily integrate the online service with your offline software. You could, for example, save a file from an offline version of Excel direct to Skydrive folder, and the file will become immediately available online and accessible to people with whom you share that folder.
Office online is handy if you needs to work with others who use Microsoft Office, or if you use Microsoft Office at work and want the benefits of using it at home and elsewhere without having to shell out for a full version.