My recollection at the time was IE4 had a working DOM while Netscape's DOM was buggy and left a lot to be desired. It was there, but it was a struggle.
I don't say that to crap on Netscape. Microsoft was a well-funded company with a lot of experts who had years of experience create applications with DOMs. Also, they had the luxury of delivering a browser for one operation system.
Netscape was a brand new company that went public 7 months after it's first release and 1.5 years after its founding. They sold investors the premise they were going to become the Microsoft of the internet. They had a fraction of the resources while they were trying to creating browsers, email clients, collaboration software, web server, and a host of other software for multiple platforms.
