Microsoft wanted to "modernize the way the platform is accessed by developers," said Richard Riley, a Microsoft director in the Office division. "We have made some of the most significant changes on the developer side of Office in the last 15 years."
"We saw that people were building a lot of internal and consumer solutions as Web applications because they were easy to deploy. Just set up a server with some HTML pages and everyone could go and get that" app, said Brian Jones, principal group program manager for Microsoft's Office solutions framework team. "That's the model we followed."
For the past 20 years, Microsoft has offered VBA (Visual Basic for Applications) as a tool for developers and administrators to add additional functionality into Microsoft Office. While VBA will still be offered in the next version of Office, now available in preview form, Microsoft will also offer the Office Cloud App Model, which uses Web standards such as HTML, CSS, OAuth, REST and Microsoft's own OData.
"There's nothing proprietary or new here. If the developer knows how to write Web apps, they can write Office apps" Riley said.
The company endeavored to apply this model consistently across Office as well as for SharePoint, for both the hosted and in-house versions of these products. "We focused on having a consistent set of APIs, so a lot of apps built for Word can also run for Excel," Jones said.
The range of apps that can be created with Web technologies equal the old style plug-ins that could be created within VBA. In a demonstration, Jones showed off a number of apps built using Web technologies. One for Outlook provided a map for any addresses that are in the text of an e-mail. Another Outlook app allowed the user to add commentary to an email. An Excel app downloaded data from the Olympics, visualized the data, and allowed the user to parse the result by country, athlete or some other attribute.
Unlike previous versions of Office, apps are stored externally, not within the local copy of Office. Office will keep URL pointers to where the organization's WebApps are stored. Office WebApps can be stored on any Web server, Jones said.