PLIB is a set of libraries to write games and other realtime interactive applications that are 100% portable across a wide range of hardware and operating systems. It's used by Majik3D, FlightGear, and others, and includes libraries for GUI widgets, sound replay, geometry, scene graph, joystick, and fonts/text.
SILC (Secure Internet Live Conferencing) is a protocol which provides secure conferencing services in the Internet. It can be used to send any kind of messages, in addition to normal text messages. This includes multimedia messages like images, video, and audio stream. All messages in the SILC network are encrypted and authenticated, and messages can also be digitally signed. SILC protocol supports AES, SHA-1, PKCS#1, PKCS#3, X.509, OpenPGP, and is being developed in the IETF. The software is delivered as SILC Client for end users, SILC Server for system administrators, and SILC Toolkit for application developers.
Publimark is a command line tool to secretly embed text in an audio file (i.e. audio steganography). Like cryptography, it uses a pair of keys: the public one can be shared, whereas the private one must be kept secret. Anybody can send a steganographic message, but only the private key owner will be able to read it. Of course, marked audio files are still playable without any noticeable change.
DIIT provides a simple tool that can hide a message inside a 24-bit colour image so that knowing how it was embedded, or performing statistical analysis, does not make it any easier to find the concealed information. It also provides a framework for implementing other steganography algorithms for use in the tool.
Visprint makes cool fractal fingerprint PNG images based on the contents of any file. The image will be different for almost every file with even slightly different contents. Visprint uses the IFS fractal generation process pioneered by Michael Barnsley. It is a way to create images that are self-similar to infinite depths. In other words, the picture is made up of smaller versions of itself. Visprint takes a hash function checksum as its input.
ansistego provides terminal-level steganography for scripts and other ASCII files (ie, protection against 'cat'). It intersperses a text/script with commented ANSI codes that cause most terminals to clear sensitive lines as soon as they are written. Only a specified front text appears. The front text is embedded in the script using ANSI-cloaked comments, so that the text appears unaltered when the script is viewed with cat, but the script can be run without any decoding stage.
libdvbcsa is a free implementation of the DVB Common Scrambling Algorithm with encryption and decryption capabilities. It comes in two flavors: a classical single packet implementation and a faster parallel bitslice implementation. The parallel implementation can take advantages of MMX, SSE, or Altivec instruction sets. The parallel implementation can process MPEG TS packets at 300Mbps or more on recent processors. It has been successfully tested on processors with different word widths and endianess.