Ekiga (formely known as GnomeMeeting) is a soft phone, video conferencing, and instant messenger application for use over the Internet. It supports HD sound quality and video up to DVD size and quality. It is interoperable with many other standards compliant software, hardware, and service providers as it uses both of the major telephony standards, SIP and H.323.
Smuxi is an irssi-inspired, flexible, user-friendly, and cross-platform IRC client for sophisticated users. Smuxi is based on the client-server model: The core application (engine) can be placed onto a server which is connected to the Internet around-the-clock; one or more frontends then connect to the core. This allows the connection to IRC to be kept up even when all frontends have been closed. The combination of screen and irssi served as the example for this architecture. Smuxi also supports the regular single application mode. This behaves like a typical IRC client; it doesn't need separate core management and utilizes a local engine that is used by the local frontend client.
GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
Pidgin-paranoia is a plugin for Pidgin (formerly known as Gaim) that provides information-theoretically secure encrypted conversations using one-time pads. Because the plugin uses a one-time pad where the secret key has the same length as the message and the key is only used once, the encryption is information-theoretically secure. This means that from the encrypted messages the contents of the messages are not revealed. In short: If you use truly random numbers to generate the key files, and if you keep them perfectly secret, one-time pads can not be broken.
Akeni Instant Messaging Server Pro is a client/server instant messaging platform that allows companies to host their own secured private IM system. The client has an user interface similar to AIM, ICQ, or MSN Messenger. It supports all the standard IM features such as chat, group conference, presence management, file transfer, offline messages, and emergency alert/notification. Extra features include contact management and optional tabbed chat sessions. The server has advanced administration tools for managing user accounts, client-side logging capabilities, and peer-to-peer file transfers. It can be set up on a private network without connecting to the Internet, and can easily be set up for use inside and outside of the company firewall.
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.
Akeni LAN messenger is a cross-platform instant messenger client. It is a P2P program that works on your LAN without the need of an Internet connection or a dedicated server. The client has an user interface similar to AIM, ICQ, or MSN Messenger. It supports all the standard IM features such as chat, group conference, presence management, file transfer, and emergency alert/notification. Extra features include contact management and optional tabbed chat sessions.