TCPSAT list of TCP papers - http://www.isi.edu/tcpsat/papers.html A list of pointers to author's copies of TCP-related papers from (now closed) IETF TCP Over Satellite working group.
The Web 100 Project - http://www.web100.org/ The goal is to make 100Mbps TCP streams over wide-area networks possible for general users.
A User's Guide to TCP Windows - http://www.ncsa.uiuc.edu/People/vwelch/net_perf/tcp_windows.html A User's Guide to TCP Windows
T/TCP Home Page - http://www.kohala.com/start/ttcp.html Historic description of T/TCP. Includes links to RFCs and source code. Not being updated since Richard W. Stevens has passed away.
Prioritizing empty TCP ACKs with pf and ALTQ - http://www.benzedrine.cx/ackpri.html An OpenBSD-specific way to relieve TCP performance degradation due to congestion in the opposite direction across a bottleneck.
TCP/IP Resources List - http://www.private.org.il/tcpip_rl.html A meta-FAQ about TCP/IP regularly posted to Usenet.
Sally Floyd at ICIR - http://www.icir.org/floyd/ Proposed and experimental improvements to congestion control.