freeglut is intended to be a 100% plug-compatible clone, and is released under the Xfree license. The GLUT (OpenGL Utility Toolkit) is a widely used library for doing window control, keyboard, and mouse input, and other basic functions for OpenGL programs. However, GLUT is not OpenSourced - although it's source code is available under a somewhat ill-defined set of restrictions. Hence, 'freeglut'.
TuxKart is a 3D GoKart racing game with several famous OpenSource mascots participating. The game uses PLIB and OpenGL, and is portable to a wide range of OS's. There are several racecourses provided, with full information on how to add your own. Except for a few minor details, this game is essentially complete, and very playable.
IP-packetgenerator is a (ICMP/UDP/TCP)/IP packet generator written in Perl. When creating a TCP packet, it lets you specify the source and destination IP address, source and destination port, sequence and acknowledgement number, window size, and TCP flags. When creating a UDP packet, it lets you specify the source and destination IP and source and destination port. When creating an ICMP packet, it lets you specify the type, code, and mtu. Additionally, you can set the Time-to-live, set the fragmentation offset, send data within the packets, and select the number of packets to send over the wire. There are commandline and GUI versions. The configuration of packets can be read from a config file or saved to a config file.
Very Simple Network Monitor is a bash shell script CGI that monitors a number of services on a network. It currently checks for node-up, TCP service up, and UDP service up. A service or system can be put in maintenance status to avoid repetitive alarms. It is easy to customize, trigger alarms by email, or whatever you like (depends on nmap for TCP/UDP service checks). Installation is also simple. It generates HTML with all statuses, and for all services just in one view.
myNetWatchman Perl Agent is a client for myNetWatchman.com. This program is designed to capture rejected packet information from various firewall logs and forward this attack information to central analysis servers at myNetWatchman.com, which then analyze events and escalate to the provider of the source.