Browsers
HTML
Servers

Related Reading

Comparison - Browser Features - will list many of the popular Web browsers and their most important features.
Comparison - Server Features - lists all the generally-available, supported server software for the World Wide Web.
Entering the World-Wide Web: A Guide to Cyberspace
Commercial Web tools: the stampede begins
The HTML Guru!
The Tim Berners-Lee interview - The first five years of the WWW and the outlook for the next five years.