Since the earliest days of the personal computer, word processors and spreadsheet programs have been the must-have software tools for digital desktops. But a revolution in the way we create documents is under way, led by a number of new — and free — online productivity applications.

Web-based software is still in relative infancy, but it's an area that's attracting a lot of attention from heavy hitters like Google, as well as innovative developers such as Zoho and FreeThink. As the tools improve, creating and editing documents using internet-based programs could become as routine as logging into webmail sites to get your e-mail.

If your job involves creating formal documents with complex formatting, then refined and richly featured word processing programs like Microsoft Word and Corel WordPerfect — programs that come in a box and get installed on your computer's hard drive — are essential tools.

But for the rest of the population these complicated and expensive programs are often overkill, offering a wealth of features that never get touched. They're the equivalent of using a heavy-duty corporate database to catalogue a personal DVD collection.

Online word processors, on the other hand, cut out most of the extraneous functionality that average users rarely need and provide only commonly used features.

In other words, while advanced users who want to create a complex table of contents or a specialized macro will probably want to stick with hard-drive-based software for now, those who only want to do simple things like change fonts and text sizes, check spelling, perform word counts, and insert tables and pictures won't feel particularly limited by an online tool.

Beyond word processing

And online productivity applications aren't just word processors. Google Docs & Spreadsheets, as its name implies, provides the means to create both text documents and simple spreadsheets. Other suites, such as Zoho Office, have slideshow presentation applications similar to Microsoft's popular desktop-based PowerPoint.

The capabilities of these internet-based programs is relatively limited compared to what's built into traditional desktop software, making them impractical for more complex tasks.

On the other hand, online productivity applications also have some interesting advantages. Publishing a file to a blog, for example, takes just a couple of clicks in most online word processors. Some programs also provide an RSS feed option that allows for nearly instantaneous dissemination of newly edited documents to subscribers.

And many of them are either free, or can be used for a minor monthly fee.

But the most important benefit of online productivity suites is that they can make collaborative authoring — where several people are involved in the writing and editing process of a document — a piece of cake.

Since documents are stored online, users with editing permission always have access to the latest version. Changes are typically tracked and coded by user, ensuring that the original document is never lost. Users with viewing permission are usually provided notation capabilities, allowing them to comment on but not edit what they see.

Drawbacks to the virtual office

However, the main limitation of using purely online office tools and storage systems is that you're at the mercy of the network. Without network access, you can't work.

Planes, subways and cars are among the many places that users of these online applications often won't be able to access their files. Most suites do allow documents to be saved locally in a variety of formats, such as Microsoft Word, Excel or PDF, but that only helps if the user knows in advance that a particular document will be needed in a dead area. So if your home or office suffers an unexpected loss of internet access, you're offline and out of luck.

But it may just be a matter of time until this problem is at least partially solved. Google, for example, is apparently working on making Docs & Spreadsheets available offline. Another suite, FreeThink Office Online, already has a desktop edition available that integrates well with its online applications — though the desktop version isn't free.

Based on these limitations, the online productivity application revolution is not going to happen right away, but it is undeniably gaining strength. Business users might not be willing to embrace online office packages until they evolve to include more of the features they've come to rely on from their hard-drive-based software, but the fact that they're free makes them awfully appealing to non-business and small business users.

Google Docs & Spreadsheets

Google developed the spreadsheet portion of its online productivity suite, then purchased a company called Writely and combined its popular word processor to create the Google Docs & Spreadsheets suite.

With the Google name behind it, it's safe to say that Docs & Spreadsheets is expected to provide sturdy competition for products from lesser known companies.

But there is plenty of room for growth in the online office arena, and Google's product has its weaknesses. The suite is missing a presentation application, for example, and the two existing programs have a slightly mismatched look and feel that can be disconcerting when flipping back and forth between the two.

Google is reportedly in the midst of addressing both of these problems.

Zoho Office Suite

The Zoho suite includes three applications: Writer, Sheet, and Show (a presentation program).

As with Google Docs & Spreadsheets, the functionality of these online programs is relatively stripped down compared to desktop applications that get loaded onto a hard drive.

The online suite also suffers from the inability to view a list of documents associated with all three applications at the same time, which means users are forced to navigate from application to application to find specific files.

Zoho's greatest asset is its collection of complementary products, including an organization tool in the form of Zoho Planner, an instant messaging and chatting application called Zoho Chat, and Zoho Virtual Office, an online collaboration suite of services that includes a calendar, webmail and a contact manager.

ThinkFree Office Online

This suite includes a word processor, a spreadsheet and a presentation application.

Users familiar with Microsoft Office will likely find all three of these programs highly intuitive, thanks to interfaces that strongly resemble those of Word, Excel, and PowerPoint.

ThinkFree also offers something called Power Edit mode, which enables advanced features more in line with a desktop office suite, including page numbering and paragraph formatting functions.

However, Power Edit mode requires Java applets to be installed on the local computer hosting the web application, which may prove impractical for users intending to work with documents on several machines in a variety of locations.

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