MatrixSSL is an embedded SSL and TLS implementation designed for small footprint devices and applications requiring low overhead per connection. The library is less than 50K on disk with cipher suites. It includes SSL and TLS client and server support, session resumption, and implementations of RSA, AES, 3DES, ARC4, SHA1, and MD5. The source is well documented and contains portability layers for additional operating systems, cipher suites, and cryptography providers.
CyaSSL is a C-language-based SSL library targeted for embedded and RTOS environments, primarily because of its small size and speed. CyaSSL supports the industry standards up to the current TLS 1.2 level, is up to 20 times smaller than OpenSSL, includes SSL client libraries and an SSL server implementation, includes an OpenSSL compatibility layer, and offers several progressive ciphers such as RABBIT and HC-128. Dual licensed under both the GPLv2 and standard commercial licensing, it caters to a wide range of projects.
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.
Netzob supports the expert in reverse engineering, evaluation, and simulation of communication protocols. Its main goals are to help security evaluators to assess the robustness of proprietary or unknown protocol implementations, simulate realistic communications to test third-party products (IDS, firewalls, etc.), and create an Open Source implementation of a proprietary or unknown protocol. Netzob provides a semi-automatic inferring process, and includes everything necessary to passively learn the vocabulary of a protocol and actively infer its grammar. The learnt protocol can afterward be simulated. Netzob handles text protocols (like HTTP and IRC), fixed field protocols (like IP and TCP), and variable field protocols (like ASN.1-based formats).
iptables is built on top of netfilter, the packet alteration framework for Linux 2.4.x and 2.6.x. It is a major rewrite of its predecessor ipchains, and is used to control packet filtering, Network Address Translation (masquerading, portforwarding, transparent proxying), and special effects such as packet mangling.
Ubuntu Privacy Remix is a modified live CD based on Ubuntu Linux. UPR is not intended for permanent installation on a hard disk. The goal of Ubuntu Privacy Remix is to provide an isolated working environment where private data can be dealt with safely. The system installed on the computer running UPR remains untouched. It does this by removing support for network devices as well as local hard disks. Ubuntu Privacy Remix includes TrueCrypt and GnuPG for encryption and introduces "extended TrueCrypt volumes".