GNS3 - GNS3 is a graphical network simulator that allows simulation of complex networks.
Jetico BCTextEncoder - Jetico BCTextEncoder is software that ensures your text-based communications are safe by allowing you to encrypt them.
ns-3 - a discrete-event network simulator for internet systems
TheLetterEncrypter - TheLetterEncrypter is a small (14KB download) AES-based text-encryption program.
NetSim - NetSim software was created to simulate various Cisco systems. Cisco software is known around the world as being one of the best network, routing and switch systems for businesses and private use. Read more about NetSim.
GNUPGK - A GnuPG Frontend GUI made in C#.