To attract more developers to Windows Live platform services, Microsoft is launching a service for hosting interactive applications that are based on its new Silverlight technology and is announcing a general set of rules for licensing these services. However, for many of these services, high-traffic sites will have to pay Microsoft a fee or split advertising revenue with the company, conditions that competitor Google does not impose. Moreover, inconsistent licensing terms and technologies could cause confusion among potential adopters.

Silverlight Streaming Service and Terms

At the 2007 Mix conference for Web developers, Microsoft offered details about Silverlight, its new technology for creating interactive Web-based applications, which is a direct competitor to Adobe's Flash. (For detailed coverage of Silverlight, see "Silverlight Details Emerge, Expression Studio Ships".)

The company also announced a new hosted online service: Silverlight Streaming by Windows Live. The service targets small developers who want to distribute their Silverlight content widely over the Internet, but don't want to invest in the online infrastructure (e.g., storage and bandwidth) necessary to host these applications themselves. Silverlight Streaming offers unlimited streaming and up to 4GB of storage at no charge; beyond 4GB, customers will have to sign commercial deals, the terms of which will vary by usage and have not been publicly announced.

In conjunction with the announcement of Silverlight Streaming, Microsoft released new terms of use for four other Windows Live platform services.

Live Search API. This API lets developers incorporate results from Microsoft's Internet search engine into their applications. Microsoft will allow up to 750,000 queries per month at no charge, beyond which developers will have to sign a commercial deal with the company.

Virtual Earth API. Developers can use this API to incorporate mapping data, including 3D images and business location data, from the back-end platform used by Microsoft's online mapping site (which is known by various names, including Live Search Maps). Microsoft will allow each licensed application to make up to 100,000 queries in any 24-hour period and to display up to 3 million map images per month at no charge. Higher usage will require commercial deals.

Contacts Control. Web developers can incorporate this JavaScript control on their sites to allow end users to view their Windows Live Contacts (collected from Hotmail and Messenger) on those sites. This could help participating sites establish a sense of community, although lack of presence information will limit the usefulness of this control. There is no user limit or fee for this control.

Spaces Photo Control. Web developers can incorporate this JavaScript control to allow users to view and select their Windows Live Spaces photos on their Web sites—for example, a third-party photo printing site could let users order prints without requiring them to upload their photos separately to that site. There is no user limit or fee for this control.

Future Pricing Model

Also at Mix 07, Microsoft announced "a single, easy-to-understand pricing model" for Windows Live platform services, as follows:

• Prerelease services are free, although some usage restrictions might apply (e.g., maximum number of queries per day)
• Once the services emerge from beta, a third-party may allow up to 1 million unique users per year to access a Live platform service through its site or application without incurring a charge from Microsoft
• For any application that allows more than 1 million unique users to access a Windows Live platform service, the licensee must pay US$0.25 per unique user per year for each platform service accessed, or must engage in an advertising revenue-sharing deal with Microsoft, the details of which were not disclosed
• Controls are an exception and will remain free for third-party use.

Oddly, none of the services mentioned previously—that is, none of the services listed on Microsoft's Web page that contains these terms of use—adhere to these rules. All five of them are exceptions.

Numerous other Windows Live platform services are in prerelease testing, such as the Live ID API, which allows third-party developers to incorporate Microsoft's Live ID (formerly known as Passport) authentication service on their sites, and the Live Expo API, which enables programmatic access to classified advertisement listings on Microsoft's Live Expo site. Microsoft is also rumored to be building services that will let third-party applications access presence information from Live Messenger (so a user could see if his Messenger contacts are online, away, busy, and so on, from within the third-party application), and Calendar information from Hotmail (or perhaps a different forthcoming calendar service). The Windows Live Platform terms of use might apply to these services once they emerge from beta, but given that every service announced so far is an exception to the standard terms of use, developers should carefully check the full terms for each service before incorporating it.

A Work in Progress

Overall, the Windows Live platform strategy is very much a work in progress, as shown not only by the inconsistent licensing terms but also by a seemingly uncompetitive business model and differing underlying technology. While none of these problems is crippling by itself, the combination could cause confusion and stifle developer interest in Microsoft's platform services before they get off the ground.

Business strategy. Microsoft's business strategy for Windows Live platform services is unclear. Traditionally, Microsoft has tried to build developer support for its platforms by freely documenting its APIs and making its developer tools better and cheaper than competitors' tools. Then, it has made money selling the actual platform products, such as Windows Server. With platform services, the analogous business model would be to make the platform services free, and then display advertisements directly on the third-party sites (e.g., sponsored search listings next to the regular search results), which is precisely the approach Google is taking. By trying to cover the costs of high usage by imposing per-user charges, Microsoft could drive ambitious Web projects away from Microsoft's platform services, especially those that begin small but grow quickly.

Multiple technologies. Unlike most successful developer platforms, most notably Microsoft's own .NET Framework, the Windows Live platform services were designed independently of one another and don't use a consistent underlying technology. For example, some are based on Web services and the Simple Object Access Protocol while others use JavaScript. Therefore, skills gained by a developer in the course of using one service don't necessarily apply to others.

Resources

Microsoft's Silverlight site is at www.silverlight.com.

The Windows Live developer site, including links to API documentation and downloadable SDKs, is at dev.live.com.

Terms of use for Windows Live services are at dev.live.com/terms/.