This is about a month too late, but Microsoft has finally responded to a question I posted about Internet Explorer 4.0. If you check out the "Letters from our Readers" page at the Microsoft Web site, you will find the following answer to my once-burning question about IE4:
Q: Brad Chase describes the current release of IE4 as a beta despite the fact that all of Microsoft's other sites called it a "platform preview." How about clarifying this issue and sticking with a single word for it. So which is it, beta or "platform preview"? Is platform preview just another way of saying beta?
A: The Platform Preview is certainly a beta release in many respects, but there was a very good reason for giving it a different name. This release is intended exclusively to give software developers and Web-site authors a head start building content for the new version of Internet Explorer. The Platform Preview doesn't contain the final user interface or all the functionality slated for the release version. For this reason, it doesn't give users a complete picture of what's to come in the final product, which is what you'd expect from a beta product. When Microsoft releases the version we're calling "beta" in the next month or so, it will give users a pretty solid take on the final release version. The Platform Preview, on the other hand, allows a first look at the product as a platform that Web authors and developers can use to deliver much more exciting and richer content.
So which is it, beta or "platform preview"? :)