Vintners.Net LinkChk
The RFCs at IETF.org (1766 lang abbrev, 1945 http1.0, 2068 http1.1)
International Standards Org. (useless)
Internet Mail Consortium (useless)
The Official HTML Spec. (W3C HTML Docs)
Sandia HTML ref man
NCSA HTML Primer
Java docs at javasoft
The Web Robots page (robots.txt)
HTTP Cookies Spec (from Netscape)
HTTP browser response codes (old)
UTC JavaScript lab
DevEdge online (developer.netscape.com)
javascript tutorial (keller.com)
Microsoft MSDN online, DHTML Reference manual