Microsoft's approach with Internet Explorer as outlined in a blog post by Dean Hachamovitch, the Corporate Vice President for Internet Explorer, is to implement standards as they become site-ready for broader adoption.
For developers, this means that they can write sites to Internet Explorer and be confident that it is based on stable HTML5 and will work in future browser upgrades. For users, it means that sites continue to work as they upgrade their browsers and they don't get locked in to older browsers.
At the same time, Microsoft sees an important need in continuing to drive experimentation and testing of new specifications in the standards organizations. It is part of the process of ensuring that specifications are actually ready for real-world usage.
The new HTML5 Labs Web site is the place where Microsoft's Interoperability Labs will publish prototype implementations of certain unstable and in-progress W3C, IETF, ECMA and other standards specifications still undergoing a lot of change. So, developers should expect that code and web pages based on these prototypes will have to be re-written as the specifications mature.
The first two prototypes we are delivering today are Web Sockets and IndexedDB.
WebSockets is a technology designed to simplify much of the complexity around bi-directional, full-duplex communications channels, over a single Transmission Control Protocol (TCP) socket. It can be implemented in web browsers, web servers as well as used by any client or server application. The WebSocket API is currently being standardized by the W3C and the WebSocket protocol is being standardized by the IETF.
For its part, IndexedDB is a developing W3C Web standard for the storage of large amounts of structured data in the browser, as well as for high performance searches on this data using indexes. IndexedDB can be used for browser implemented functions like bookmarks, as well as for web applications like email. IndexedDB also enables offline scenarios where the browser might be disconnected from the Internet or server.
The details of the HyBi protocol underlying WebSockets are being hotly debated in IETF right now, and the IndexedDB spec will soon be updated to reflect decisions made at a recent W3C working group meeting.
Microsoft calls developers to experiment with these prototypes and tell the company and other working group participants whether the APIs are usable.
Other implementers can use these prototypes to determine whether we have interpreted the specifications in the same way, and a larger audience can get a better sense of what potential will be unlocked when these specifications have stabilized into interoperable implemented standards.