TCP Vegas
Princeton University TCP Vegas work.

A User's Guide to TCP Windows
A User's Guide to TCP Windows

Enabling High Performance Data Transfers on Hosts
TCP performance tuning notes from PSC

NASA TCP Research
including SACK/FACK, larger initial windows, and TCP over Satellite

Increasing TCP's Initial Window
including links to simulations, experiments, talks, and the RFC

Proposed Changes to TCP
a set of pointers from Sally Floyd

Automatic TCP Buffer Tuning Research
at PSC

Global Optimization with End-to-End Congestion Control: Pointers to the Literature
links from Sally Floyd

The TCP-Friendly Website
TCP-friendly algorithms and TCP performance models

ECN
Sally Floyd's ECN (Explicit Congestion Notification) links

RED
Sally Floyd's RED (Random Early Detection) links

Research Projects
Reports of experience with TCP SACK at UCLA

The Web 100 Project
The goal is to make 100Mbps TCP streams over wide-area networks possible for general users.

TCP Smooth Start
A refinement to slow start algorithm.

TCP Selective Acknowledgment Options
Links from Sally Floyd.

Equation-Based Congestion Control for Unicast Applications
Research papers describing experience getting TCP-compatible throughput from rate-based (rather than window-based) approaches. Since resulting traffic stream is less bursty, this approach is suitable for streaming multimedia applications that need congestion-avoidance properties.

T/TCP Home Page
Historic description of T/TCP. Includes links to RFCs and source code. Not being updated since Richard W. Stevens has passed away.

TCP/IP Resources List
A meta-FAQ about TCP/IP regularly posted to Usenet.

Prioritizing empty TCP ACKs with pf and ALTQ
An OpenBSD-specific way to relieve TCP performance degradation due to congestion in the opposite direction across a bottleneck.

TCPSAT list of TCP papers
A list of pointers to author's copies of TCP-related papers from (now closed) IETF TCP Over Satellite working group.