Terminal Mixer allows sharing the stdin/out/err of a process through a Unix socket, TCP, or raw ethernet (the latter only on Linux). It allows sharing a pseudo-terminal as well, for terminal-aware applications. The users can be allowed only to watch, or even to contribute. You can run your favourite 'vim' or 'bash' and access it remotely, even with multiple users using them.
alph implements and analyzes historical and traditional ciphers and codes, such as polyalphabetic, substitutional, and mixed employing human-reconstructable algorithms. It provides a pipe filter interface in order to encrypt and decrypt block text to achieve transparency. The program is meant to be used in conjunction with external programs that transfer data, resulting in transparent encryption or decryption of information. The program can thus be used as a mail filter, IRC filter, IM filter, and so on.
psyced is a distributed chat and messaging system based on the Protocol for SYnchronous Conferencing. PSYC is multicast and routed between servers and clients in a scalable and efficient way, but users can also comfortably use IRC clients, telnet, Web chat, WAP, or Jabber to enter the network. psyced also communicates with the network of Jabber/XMPP servers and hosts programmable chat rooms for all of these technologies at once. It also provides gateways to several IRC networks, but unlike IRC, everyone can run a server and be an equal member of the PSYC network. It supports PSYC, XMPP, IRC, TELNET, HTTP, Applet, SMTP, WAP, XML, RSS, and TLS.
x11vnc allows one to remotely view and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. It is designed to be compatible with all Unix variants and Mac OS X, and depends on a small set of standard libraries. It supports SSL/TLS and VeNCrypt encryption, Unix password logins, single port access, Zeroconf, file transfer, and UltraVNC extensions. It is part of the LibVNCServer project.