An universal TCP client.
Pure Java Network Tools
FreeBSD Multi PPP daemon
Robust and flexible VPN network tunnelling
Create nested tunnels through HTTP proxies
Encrypted UDP based FTP with multicast
Serial <-> TCP/IP, Serial <-> UDP/IP, TCP/IP <-> UDP/IP
High performance, production quality STUN server and client library
Snare Enterprise: bit.ly/Snare-Trial
Makes it easier to resolve TCP/IP connection errors.
An easy-to-use anti-spam email gateway
Pen is a load balancer for udp and tcp based protocols.
Lightweight fully extendable client/server application framework
Various TCP/IP servers, clients and network management tools
Highly configurable SNMPv1/v2c/v3 application-level proxy
A free high-performance alternative to TCP sockets
An impressive early implementation of TCP/IP