distributed.net is a loosely knit group of computer users from all of the world that is taking up challenges requiring lots of computing power (most notably the RC5, DES, and OGR cracking contests). It is simple to participate in the challenges by downloading and running their client software (which uses idle CPU time to complete its tasks).
trf is an extension library to the script language tcl, as created by John Ousterhout. It extends the language at the C-level with so-called "transformer"-procedures. With the help of some patches to the core the package is able to intercept all read/write operations on designated channels, thus giving it the ability to transform the buffer contents as desired. Existing transforms include Base64, UUencode, Hashes (SHA, MD5, ...), error correction codec, zlib-based compression, script level transforms.
Zebedee is a simple program to establish an encrypted, compressed tunnel for TCP/IP or UDP data transfer between two systems. This allows traffic such as telnet, FTP, and X to be protected from snooping as well as potentially gaining performance over low-bandwidth networks from compression.
Botan is a crypto library written in C++. It provides a variety of cryptographic algorithms, including common ones such as AES, MD5, SHA, HMAC, RSA, Diffie-Hellman, DSA, and ECDSA, as well as many others that are more obscure or specialized. It also offers SSL/TLS (client and server), X.509v3 certificates and CRLs, and PKCS #10 certificate requests. A message processing system that uses a filter/pipeline metaphor allows for many common cryptographic tasks to be completed with just a few lines of code. Assembly and SIMD optimizations for common CPUs offers speedups for critical algorithms like AES and SHA-1.
GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.
The OpenAI site is centered around an Open Source project and community involving artificial intelligence. The project itself is the creation of a set of tools that are considered to be models of human intelligence or biomimicry. These tools are intended to be integrated into applications or used stand alone for research.