RFC Editor:Collates Request For Comments documents. Explains the RFC process, and includes a searchable database of RFCs.
The Internet Report (IETF Weekly Updates):A table of new Internet Drafts and RFC's that come out each week, with synopses. Archived summaries go back to June 1999.
Active IETF Working Groups: A directory of the Internet Engineering Task Force groups and their web pages.
Free Protocols Foundation: Independent public forum supporting patent-free protocols. Includes policies, papers, a mission statement, and a list of free protocols.
IETF Internet Drafts: List of documents organized by alphabetized subjects.
Internet Encyclopedia: Overview of Internet protocols.
Internet protocols: General comments on protocol design, and good reference material on a few protocols (especially mail-related; also ftp, time, and misc) by Dan Bernstein.
Internet2: A consortium led by universities working in partnership with industry and government to develop and deploy advanced network applications and technologies, accelerating the creation of tomorrow's Internet.
Port Numbers and Services Database: Well known port numbers for TCP and UDP, from Internet Assigned Numbers Authority (IANA).
RFC Sourcebook: Description of protocols, file formats, glossary of terms, RFCs.
The Kermit Project: A protocol that transfers text and binary files without errors between diverse types of computers over potentially hostile communication links, and a suite of communications software programs; Columbia University.
XNS.org: Independent organization managing the eXtensible Name Service, an open protocol and open-source platform for universal addressing, automated data exchange, and privacy control. Includes an overview, charter, history, and specifications.