XML, CSS, and Mozilla
While Internet Explorer 5 is only a preview (the version used here is preview 2, and rumor has it that there will be another beta test version before the package is officially released sometime in 1999), it still enjoys a more official status than Mozilla. Furthermore, IE5 is pretty stable and fairly complete. Mozilla is another story. Netscape's open source policy for Mozilla, by which anyone is welcome to contribute to the code, means that the end results are less visible and less predictable. However, the compiled versions available on the Internet and gossip among the developers indicate that Mozilla's support for XML will be more solid than Microsoft's.
I personally doubt there was a battle of the browsers between Microsoft and Netscape. To the best of my knowledge, Netscape makes far more money selling Web servers and supporting software than it could ever have made from selling browsers. Microsoft did start giving away Internet Explorer for nothing, but it wasn't the browser market they were interested in so much as trying to protect Windows' position as an Internet platform. Besides, there are other (and even better) browsers such as Opera, Amaya, Mosaic, Likse, and Lynx, to name just a few of the better known ones. However, even if it isn't true it does make a good story and there is little doubt that Microsoft is slowly gaining more and more ground (an amazing feat considering the very late and very mistaken start they made).
Development of the Netscape Communicator continues in parallel (4.5 is the current official release) and it is anyone's guess when, or even if, Mozilla will become an official product. Netscape's policy is to take the best parts of this public browser and incorporate them back into the mainstream product. Meanwhile, although the package is extremely unstable, it can be exciting and extremely educational to experiment with it.