Tool Command Language

https://www.tcl.tk/

Tool to replay saved packet capture files

https://github.com/appneta/tcpreplay

Packet sniffer which displays TCP information like top(1)

https://BSDforge.com/projects/net-mgmt/tcptrack/

Set of configuration scripts for the TCSH shell

http://tcshrc.sourceforge.net/

Trivial Database

https://tdb.samba.org/

Toolkit for converting data between 8-bit legacy encodings and Unicode

https://scripts.sil.org/TECkit

GLib utility library for the Telepathy framework

https://telepathy.freedesktop.org/

Logger utility library for the Telepathy framework

https://telepathy.freedesktop.org/

Talloc based event loop library

https://tevent.samba.org/

Path searching library for TeX

Library for Japanese pTeX and its tools

Meta-port that creates a site-local TEXMF directory

Texinfo to HTML converter

http://texi2html.cvshome.org/

Typeset documentation system with multiple format output

https://www.gnu.org/software/texinfo/

Fixes and tidies up HTML files

https://www.w3.org/People/Raggett/tidy/

Utility to clean up and pretty print HTML/XHTML/XML

http://tidy.sourceforge.net/

Utility to clean up and pretty print HTML/XHTML/XML (with shared lib)

http://tidy.sourceforge.net/

Library and program to validate and fix HTML

http://tidyp.com/

Tools and library routines for working with TIFF images

http://www.simplesystems.org/libtiff/

MIDI to PCM software synthesizer

http://www.onicos.com/staff/iz/timidity/

Analogous to cdb, but faster

https://www.corpit.ru/mjt/tinycdb.html

server which provides telnet(1) access to one or more tty ports

Shell wrapper for wish (Tk)

Graphical toolkit for Tcl

http://www.tcl.tk/

Graphical toolkit for Tcl

http://www.tcl.tk/

Graphical toolkit for Tcl

http://www.tcl.tk/

Tk library to access to X Shaped Window Extension

https://www.cs.man.ac.uk/~fellowsd/tcl/shapeidx.html

Extremely portable perl-based make utility

http://tmake.sourceforge.net/

A textbased (console) MSN client

http://tmsnc.sourceforge.net/

Enhanced ftp client from NetBSD

https://ftp.netbsd.org/pub/NetBSD/misc/tnftp/

Enhanced FTP server from NetBSD

https://ftp.netbsd.org/pub/NetBSD/misc/tnftp/

Anonymizing overlay network for TCP

https://www.torproject.org/

Efficient way to prepare zipfiles for BitTorrent

http://trrntzip.sourceforge.net

Trusted Platform Module (TPM) emulator

http://tpm-emulator.berlios.de/

Traditional (K&R-style) C preprocessor

https://www.NetBSD.org/~dholland/tradcpp/

The BPF Traffic Collector

Meta-port for Transmission BitTorrent client

http://www.transmissionbt.com/

DEC-XTRAP extension headers

Open-source TCG Software Stack

https://sourceforge.net/projects/trousers/

Allow non SOCKS aware applications to use SOCKS without modification

https://tsocks.sourceforge.net

Tab Window Manager for the X Window System

MPEG Audio Layer 2 encoder

http://twolame.sf.net/

Data compression library with low memory usage

https://www.oberhumer.com/opensource/ucl/

Common subroutines for UCL mbone applications

http://www-mice.cs.ucl.ac.uk/multimedia/software/common/

Command-line tools for building TCP client-server applications

https://cr.yp.to/ucspi-tcp.html

DNS resolver library with sync and async queries

https://www.corpit.ru/mjt/udns.html

Fast copy utility for UFS filesystem

http://people.freebsd.org/~simokawa/ufs/

Convert MagicISO UIF files to ISO9660

http://aluigi.altervista.org/mytoolz.htm

Extract, view & test ACE archives

http://www.winace.com/

Allows files to be extracted from ARJ archives

http://www.arjsoftware.com/