A view of the Excel Web App, debuting as part of a limited technical preview. Click image for larger screenshot. Image credit: Microsoft

Microsoft this morning is rolling out a technical preview of its Office Web Apps -- the long-awaited, Web-based versions of Word, Excel and other programs from its widely used Office productivity suite.

However, the company is careful to call it a "limited" technical preview, and it ain't kidding. Invitations to try the Office Web Apps will be presented to a relatively small number of Windows Live users, and even those who get into the program will find that it's lacking some key features -- most notably, the ability to actually edit a document in the browser-based version of Microsoft Word.

Don't worry, the company says, it's not done with its work.

The Web Apps are Microsoft's first big entry into a segment of the market where Google and others have been operating for several years now. For now, the limited technical preview of the Word Web App will let users view Word documents, but that's essentially it. Editing and viewing will be possible in the PowerPoint Web App, and the Excel Web App will let users view, author and collaborate with others online.

"More is definitely coming," said Michael Schultz, director of marketing for the Office team, explaining that the idea behind the technical preview is to roll the apps out in limited form to get feedback. A fuller-featured beta release is scheduled for the fall, with the final versions slated to debut in the first half of 2010.

Microsoft had previously missed its target of debuting the Web Apps preview by the end of August.

Your best chance of getting an invite to the technical preview is to use the company's Windows Live SkyDrive service, signing in with your Windows Live ID. It will be available in the U.S. and Japan. Schultz said "several thousand" people will be put into the technical preview, although there's not a specific cap.

The Skydrive file-storage service will serve as a hub for the Web Apps. The applications will work on PCs and Macs, and they will work in Internet Explorer, Safari and Firefox. They also are expected to work in Linux in Firefox 3.5 or greater.

The company will open things up to more users when the beta debuts. Microsoft also is planning to release a Web-based version of its OneNote application, but that, too, will come at a later date.

For the record, the official name of the programs will indeed be Office Web Apps, Schultz confirmed. A survey conducted by Microsoft previously had hinted at the possibility of more fanciful names, such as Ensemble, Optro or ArcLight.

When they're released in final form, Office Web Apps will be available to consumers through Windows Live at no cost, supported by ads. In addition, Microsoft still plans to offer Office Web Apps to businesses as pure "cloud" services, from its own data centers, through its subscription-based Microsoft Online services. Alternatively, companies will have the option of running the apps from their own servers.

Post updated at 11 a.m. with additional information and background.