A while back I was on a panel fielding questions on SharePoint 2010. I was asked “what was the single, most important feature in the new version?” Sounds like an easy question, right? For me it was tough because there are a ton of new features in SharePoint 2010—from the new and improved UI, to the new service application architecture, to the social computing improvements. But, the answer that first came to mind, and the one I still believe might be the most important feature is Office Web Apps.

This major feature opens up many new collaboration possibilities but, frankly, I don’t think it’s getting much press. For those of you who haven’t heard of Office Web Apps yet, this feature allows you to view and edit Word, Excel, PowerPoint, and One Note right from the browser.

This shouldn’t surprise you much. Microsoft has had Outlook Web Access built into Exchange for years and having this for the other apps was long overdue. While it may be late, at least they did it right. Here are just a few of the use cases where it will make my life a lot easier:

  1. I’m using a browser-only terminal in an airport or Internet café, and I need to make some edits to a PowerPoint deck that one of my colleagues just published.
  2. I’m working at home and am trying to find the right Word document that I created a while back. For each file, I have to wait for it to completely download so I can open it. Some of these files are big, and it’s taking forever.
  3. I work frequently with my clients’ environments through their extranet. Each time I open up an Office file, I have to type in my credentials repeatedly.

Some of the features include concurrent editing with Excel files, meaning you can have several people all editing the same file at the same time. Way cool! Another is dynamic saving, which works in all apps except Word. This means there is no save button and changes are automatically saved back to the server.

Windows browser support includes IE 7 and IE 8, Firefox 3.5 and later, and Safari 4 and later. Expect good results when working from a Mac or Linux machine. You also have pretty good mobile support for viewing, but not editing files. Office Web Apps works on Windows Mobile, BlackBerry, iPhone, and some others.

Don’t look to Office Web Apps to replace your Office client, rather, it’s a complementary offering. Although the viewing support is fantastic, editing is limited and is only practical for lightweight tasks. For example: you can edit existing charts in Excel, but you can’t create new ones. Despite this limitation, it’s still a big step in the right direction, and I fully expect this to improve over time.

Silverlight is not a requirement in this release, but if you’ve installed it, Office Web Apps will detect it and use certain features. I’m a huge fan of Silverlight and see it as the application platform of the future. In a future release, I’d expect to see much richer and deeper Silverlight integration. I’ll even go out on a limb and predict that full versions of Office will someday be based on Silverlight, run entirely from the cloud, and be as full-featured as the desktop version you have today. Of course, there is intense competition from Google Apps and others; Office Web Apps further solidifies Microsoft’s intention to provide cloud-capable solutions.

Even though Office Web Apps integrates with SharePoint 2010, it isn’t installed by default. You can download and install it on either Foundation or Server. You’ll also need to create new service applications for it and designate the server(s) in your farm that will run the new services.

To integrate with SharePoint, you must either have or purchase Office client licenses. So each user who uses Office Web Apps needs must have an Office license, whether Office is installed or not. However, Microsoft has just released it to SkyDrive users for free. SkyDrive is a good place to give Office Web Apps a test drive to see how you like it. Just go to skydrive.live.com. For now, SkyDrive supports only English, but I’m told all languages will eventually be supported. For those using SharePoint Online, expect Office Web Apps support when SharePoint 2010 is available later this year.

For those of you who are planning or building your SharePoint 2010 environments, please make sure you include Office Web Apps in the mix. You’ll find it incredibly useful, and I’m sure your users will as well. To learn more, visit http://office.microsoft.com/en-us/web-apps/.