[jmesserly]

The difference is MS stopped having people work on IE once Netscape was out of the picture. It's not like Firefox would just stop being developed. It's an open source project, after all.

[yuhong]

>The difference is MS stopped having people work on IE once Netscape was out of the picture.

IE's rendering engine and JS/CSS, to be more precise. (Look at the IE6 in Longhorn pre-releases and IE6 in XP SP2)