AppGate Security Server is an access control gateway for secure access to resources such as TCP ports, network ranges, Web pages, file shares, and remote desktops. Users connect with the cross-platform AppGate client (or any standard SSH client) and the server has a detailed configuration that says which users gain access to what under which circumstances. AppGate Free Edition is a virtual appliance running in a VMWare image and is limited to a maximum of 10 concurrent users.
jmxsh is a fully scriptable command-line JMX client based on Tcl. It is simply a Tcl interpreter powered by Java/Tcl (with command-line history and editing provided by JLine) that has special command-line options for connecting to JMX servers and special Tcl commands for interacting with JMX servers. jmxsh is capable of simultaneously connecting to multiple JMX servers. There's also a "browse mode" for exploring the remote JMX namespace without knowing beforehand the names of MBeans or their properties. jmxsh and all its dependencies are distributed in a self-contained executable jar file for ease of use.
DenyThem is a program designed to protect your Linux system from malicious attacks. It is an active response system to disrupt and block dictionary attacks and DOS attacks. DenyThem by default uses /var/log/syslog and /var/log/auth.log and searches for hack attempts. When DenyThem finds enough hack attempts from a single host, it will add a DROP statement to your system's firewall, thus preventing future attacks. DenyThem uses iptables, so it will only work on Linux or any other system that uses iptables. It can also block traffic from specific countries.
P6P is a decentralized public virtual network designed for traversing NAT. It's useful mainly for peer-to-peer applications that don't implement NAT traversal themselves. It uses an unrouted segment of IPv6 (Unique-local), so it doesn't collide with other networks. It does not implement any additional security.
IPFire is a Linux firewall distribution that is built from source and comes with lots of additional features. It is easy to set up and administer. It features a firewall with stateful inspection, a content filtering engine, traffic control (QoS), VPN technology, and a lot of logging.