Although Google Docs and Zoho are both flawed, Microsoft could hardly have expected to take this competition lying down. The Redmond-based giant is currently in the process of readying a fully web based version of its Office productivity suite, due to launch simultaneously with the release of Office 2010.

MS Word WebUnlike its competitors, Microsoft's online suite reproduces .doc and .docx files with absolute fidelity, down to the smallest detail. The results are jaw dropping. Fonts, page spacing, headers, footers, auto-text entries, footnotes - everything appears exactly as it does in the desktop version of Word. Images show up where they should, even when placed above or behind text. Documents that mix page sizes, or that alternate portrait and landscape modes from page to page, load correctly. And, most miraculous of all after experiencing the competition, printing is flawless.

The PowerPoint files I tried yielded similarly impressive results. Images retained most of their quality, and text remained where it should. And unlike Google Docs or Zoho, the PowerPoint Web App managed to preserve animated transitions between slides.

You'd be forgiven for assuming that Microsoft relies on ActiveX controls or other IE-only trickery to achieve all this, but you'd be wrong. Internet Explorer users are offered an improved file upload UI, but other than that, everything renders the same in all of Microsoft's supported browsers, which includes not just IE 7+, but Firefox 3.5+ and Safari 4+, as well. Just for fun I tried Google Chrome, too, and even though that browser isn't formally supported, everything looked fine. That's it; no addons or plugins are required, but if you do install Silverlight, fonts look crisper and document load times improve somewhat.

But there must be a catch, right? Sure, and it's a big one. Microsoft's applications don't really work. During the Technical Preview, documents imported into the online versions of Word and PowerPoint are read only. Mind you, that's nothing to sneeze at. If you're looking for a surefire way to read and print Word 2007 documents from Linux, for example, these apps are already a godsend. But whether Microsoft can recreate the editing experience of its desktop apps remains to be seen.

MS Excel WebThe Excel Web app does allow editing, and the results are mixed. Like its siblings, it reproduced Excel files with far greater fidelity than either Google Docs or Zoho. This was especially true for embedded graphs, which rendered exactly as they do in Excel 2007, down to the fonts and coloring. Changing figures on the worksheet caused the graphs to be redrawn in real time, which was impressive to watch.

Equally impressive were the app's collaboration capabilities. Multiple authors can open the same document simultaneously, and when one author makes changes, all the other browser windows are updated with the new figures in real time. (It's worth noting, however, that Microsoft says a similar capability will not be available in the Word Web app at launch time. Apparently there are limits to Microsoft's AJAX approach.)

Notably absent was any kind of revision history like what Google Docs and Zoho offer. It was fairly trivial to corrupt an entire worksheet with a few clicks of the mouse, and given that the document saves itself automatically at regular intervals, the Revert to Saved button wasn't much comfort. Hopefully this situation will improve as the suite matures.

More troubling were the features the suite didn't support. While the other suites generally discarded elements of spreadsheets they couldn't parse, Excel Web App warned me that files containing "VBA, shapes, or other objects" might not import properly. Worse, when such files did load, the presence of such objects meant they couldn't be edited. It seems the complex Office file formats can be a bit much for online applications to handle, even for Microsoft itself.

The final version of the Office Web Apps will also include a web based version of OneNote, but that application isn't part of the Technical Preview and wasn't available to demo.

Microsoft plans to offer several versions of its web based Office at launch. The consumer version will be ad supported and offer similar web publishing features as its competitors (including the ability to embed Word documents in web pages, formatting and all). Microsoft will also offer a hosted subscription version for businesses, with improved document management and workflow features. Customers who prefer to run the suite on their own servers will be able to do so if they buy a volume license to Office 2010.

That last option underlines Microsoft's view of Office Web Apps as a companion to the traditional desktop suite, not a substitute. Promised integration between Office Web Apps and Office 2010 will allow Office 2010 users to save documents to the web and open them from the web directly.

I didn't manage to get Office Web Apps working with the Technical Preview of Office 2010, but I did get it working with Office 2007 on Vista. I needed to be using Internet Explorer to make it work. I could click "Open in Word" in Word Web App and the document would download and open in Office 2007. From there I could make changes, and when I hit Ctrl-S the changes would be saved back to the document stored online. If I then reloaded the document in the Word Web App, I would see all the changes.

It's nothing more impressive than what you can do right now when you open a Word document from a networked share, but it shows how Microsoft is thinking about Office Web Apps and the desktop apps as a unified whole.

OUR VERDICT

While the Office Web Apps are currently only available as a Technical Preview (with a formal beta program to be announced later this year), they're already shaping up to become a formidable challenge to Zoho and Google Docs.