New York - Over the years, as I've added laptops, smartphones and tablet computers to the collection of desktop machines I use at home and work, it has become a chore to keep track of which files are where. Once I bring in friends and colleagues to collaborate on some of these documents, the task becomes downright painful.

Because my devices are all connected to the Internet in one way or another, I'm able to take advantage of syncing features that come with the leading word processing and spreadsheet packages. Microsoft's Office is the industry leader and a good option when you're working with others. The main drawback is the price - $100 a year for up to five computers and five phones. Google and Apple have free or cheaper alternatives that may fit your needs better, but both have limitations.

Which one will work best for you? That depends on your sharing and syncing needs.

Working on one computer

The Office package, which includes Word for word processing, Excel for spreadsheets and PowerPoint for presentations, is an excellent option when you have to collaborate with a lot of people.

Like it or not, Office is what just about everyone else uses, and using it yourself will save you from headaches when exchanging files with others. Word and Excel are both packed with features, more than most people will ever need.

If you're working on only one computer, you probably don't need the $100-a-year subscription. For a one-time payment of $140, you can purchase and install Word, Excel and PowerPoint on a single Windows or Mac computer. Keep in mind, the Mac package was released in late 2010 and will likely get an update next year. A subscription gets you the update for no extra charge.

Office isn't a viable option if your computer is a tablet. The Office software can be installed only on Windows tablets - not the more prevalent iPads or Android tablets. You can work with Word and Excel files on those devices using software made by other companies or Web-based apps made by Microsoft. But you'll be sacrificing the power of having Microsoft's software installed right on your device, and you'll need a continuous online connection with Microsoft's Web Apps.

In recent months, Microsoft has released versions of Office for the iPhone and Android phones, but functionality is limited. The apps are designed for viewing and light editing, not for complex spreadsheets. The apps come with the $100 annual subscription. There's no option to buy them outright with a one-time payment.

If you have a Mac, consider Apple's iWork package, which comprises of Pages for word processing, Numbers for spreadsheets and Keynote for presentations. Each app is $20, so you pay $60 for the package. Comparable apps are available for iPads and iPhones - for $10 each, or $30 for the set.

The Apple package is cheaper than Microsoft's. It's not as rich on features as Office, but it has all the things most people need. It's also better at automatically saving interim revisions, in case you need to go back to an earlier draft.

The problem comes with sharing files. It's likely that the recipient of your file won't have Pages or Numbers to read it. Apple currently doesn't make the software for Windows or Android devices. You can export files to Microsoft and other formats, but that's an extra step to take, and you risk losing some of the formatting. Pages and Numbers are good primarily for Apple users who create documents only for themselves.

That said, Apple is releasing an online version of iWork this fall, opening it to Windows and Android users as long as they have continuous online connections. Apple hasn't announced details on pricing.

Google Docs is a package that works on any computer with a Web browser - Windows, iPhones, iPads, Android and, of course, Google's own operating system for laptops, Chrome OS.

It's free, and there's no software to install - everything runs on Google's servers over the Internet. Like iWork, interim revisions are automatically kept in case you need an old draft.

But Google Docs is short on features. It lacks the option to automatically hyphenate words at the end of a line, for instance. Spreadsheets are limited to 400,000 cells, compared with 17 billion for Office. Google Docs also needs a constant Internet connection to run smoothly. An offline app you can enable for Google's Chrome browser is more of a stopgap. There's no spellchecking until you are back online, for instance. (That said, the online version of iWork doesn't work offline at all, at least in its beta test form.)

Both iWork and Google Docs have good auto-save features. If your power goes out, you won't lose an entire day's work. Office has a mechanism for recovering files following crashes and power outages, but it's not as reassuring as a real save.

Winner: Office for versatility, and iWork for balance of price and features.

Working on multiple computers

Google Docs is the only package that doesn't care what computer or mobile device you have, as long as you have a decent Internet connection.

Apple will have that, too, when an online version of iWork comes out. I have been trying out a beta of iWork for iCloud since early August and like how it's working so far. Although the beta lacks many of the features of the stand-alone iWork software, it has much of what I need.

Office's Web Apps software, meanwhile, is decent on its own, with more features than either Google Docs or iWork online. But it feels underwhelming compared with the robust, stand-alone offering I'm used it. That said, you won't need Web Apps if you have a Windows or Mac computer.

Office does get expensive if you want to use it on multiple computers. It's $280 for two computers and $420 for three. With multiple computers, the $100-a-year subscription starts working in your favor, though keep in mind you're paying that each and every year. Paying $280 just once for two computers is still cheaper than $300 over three years. The subscription extends to Mac computers, too. If you have only Macs, Microsoft has been offering a three-computer bundle for $150, though that's being phased out in favor of subscriptions.

The costs for Apple's programs also add up with multiple devices, but not as much. The license allows you to use apps on multiple computers, so you'll be paying $90 at most for Pages, Numbers and Keynote on regular computers and mobile devices. And that's $90 just once, not $100 a year. Apple hasn't announced pricing yet for the iCloud version, so stay tuned if you need to use it on Windows or Android devices.

When you use the programs with Microsoft's SkyDrive, Google's Drive and Apple's iCloud storage services, changes you make on one computer will appear on another. You no longer have to email files to yourself or carry USB drives, and you no longer have to worry about which copy is the latest.

I use Google Docs regularly for lightweight tasks, such as keeping my list of things to do. What I like most about Google Docs is the ability to have multiple copies open. If you make changes on two devices simultaneously, Google will figure it out and keep all copies synced within seconds.

The Apple package is headed in that direction with the iCloud edition. The updates are fast. With the stand-alone iWork software for computers and mobile devices, you can work with multiple copies if you wait a few seconds before switching. Otherwise, you'll be prompted to choose one set of changes and discard the other.

Office allows simultaneous editing through SkyDrive, but updates aren't automatic. I need to click on "updates available" on the bottom right to get the changes.

Winner: Google Docs if you don't need a lot of advance features, Office if you do. If you're in an all-Apple environment and won't need to share files with others, go for the cheaper iWork package.

Working with others

Google Docs shines when it comes to sharing documents. You can make a document available to anyone with a special Web link you give out, or you can give permission to specific users you list. For the latter, they'll need to have or get a Google account. You can specify whether recipients can only view documents, make comments or fully edit them. It's great for documents you frequently share.

When collaborating, you'll see each other's changes immediately. You don't need to worry about who has the latest file. You also don't have to worry about the operating systems or devices the others are using. All they need is a browser with an Internet connection.

But the world has yet to fully embrace Google's formats. You're less likely to have someone go "huh?" when you send someone a Word or Excel file. Plus, you may need one of the advance features for calculating something in Excel or formatting a report in Word.

With SkyDrive, you can share Office documents with a link or list of specific users, just as you can with Google Docs and Google Drive. As mentioned earlier, simultaneous editing is possible, though it's not as automatic as Google Docs.

As for iWork, Apple's iCloud doesn't have the sharing features available with the other online storage services. It's meant to share stuff with yourself. That may change by the time the iCloud software comes out. For now, the best you can do is send someone an attachment of your document. You'd then need to deal with syncing changes in various versions of the same document.

Winner: Google Docs if you don't need a lot of advance features, Office if you do. But keep an eye out for iWork for iCloud this fall.