There are few pieces of software that users touch more often than office productivity suites. The market monster is, of course, Microsoft Office, with the lion's share of all licenses for office productivity tools. But two trends -- open source and cloud computing -- are offering a new generation of Office alternatives that businesses may want to consider.

In many ways, the sheer pervasiveness of Microsoft Office means that it defines the category in terms of the basic functions that are required and the way they're presented. If you want or need to have a different sort of office productivity solution sitting on your desk, then you're going to look at options defined in large part by the ways in which they differ from Microsoft Office.

[ Before you switch from Microsoft Office to one of these alternatives, you should weigh the costs of training, file compatibility, and support. See the article "Can you really live without Microsoft Office?" and the slideshow "Office killers" ]

Both IBM Lotus Symphony and Google Docs take a basic view of the office suite, with word processing, spreadsheet, and presentation applications front and center. To a certain extent, each can succeed with this approach because each has a set of communication, collaboration, and database applications that exist apart from the personal productivity basics.

OpenOffice and Zoho are much more all-inclusive products, with different emphases based on their different primary audiences. OpenOffice adds a database manager, a drawing tool, and an equation editor to the basic tools to create a suite well matched to academic and research-oriented desktops. Zoho has the largest package of functions, with a planner, a notebook, a wiki, dedicated chat, and an e-mail client added to the personal productivity side, and eight applications, from database to CRM, available in a business applications section.

Jump to the review of each office productivity suite:
Google Docs
IBM Lotus Symphony
OpenOffice.org
Zoho