TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
Snoop is a GNU/Linux file descriptor monitoring tool inspired by FreeBSD's 'watch'. It goes beyond simple TTY snooping by allowing the interception of any file descriptor. You can attach on the fly to regular files, TTYs, named pipes, character devices, and pretty much anything that is represented by a file descriptor and addressable in the standard name space.
ConMan is a serial console management program designed to support a large number of console devices and simultaneous users. It supports local serial devices, remote terminal servers (via the telnet protocol), IPMI Serial-Over-LAN (via FreeIPMI), Unix domain sockets, and external processes (e.g., using Expect to control connections over telnet, ssh, or IPMI Serial-Over-LAN). Its features include logging (and optionally timestamping) console device output to file, connecting to consoles in monitor (R/O) or interactive (R/W) mode, allowing clients to share or steal console write privileges, and broadcasting client output to multiple consoles.
Libptytty is a small library that offers pseudo-TTY management in an OS-independent way. It was created out of frustration over the many differences of PTY/TTY handling in different operating systems for use inside "rxvt-unicode". It also offers session database support (utmp and optional wtmp/lastlog updates for login shells) and supports forking a proxy process after startup and dropping privileges in the calling process. It offers C++ and C-only APIs.
The sniffy project can trace/log the data of any pseudo terminal in the system. Due to the way the terminal works, such a terminal trace provides complete information of what happened on the terminal screen, and sniffy is able to display/replay this information. It consists of a kernel module able to connect/hook on the pseudo terminal, a program to display the contents of any pseudo terminal on the fly, a daemon process tracing the pseudo terminal content into the file, and a replay program to replay any stored pseudo terminal session.
mimic is a server that mimics Internet servers. It includes imitators for ftpd and telnetd, and can be extended with scripting to support other types of imitation. Users will believe they are connected to authentic services (such as ftpd or telnetd) but will never be able to log in. Everything that they type is logged. In addition, scripting new imitator services is simple. The program includes a one-liner example of a fully-functional echo server. The project's goal is to create a script for imitating most, if not all, popular Internet services.