ENet for C# wraps the C-language ENet networking library. For games and other realtime applications, if you use TCP, old data can hold up newer data, even if it is no longer relevant (old positions, etc.). Your players will perceive any lost packet as a "lag burst". ENet supports multiple in-order streams of data, and allows you to decide on reliability on a per-packet basis. The library is useful for both client-server and peer-to-peer architectures.
Sanewall is a firewall builder for Linux that uses an elegant language abstracted to just the right level. This makes it powerful and easy to use, audit, and understand. It allows you to create very readable configurations even for complex stateful firewalls. Sanewall can be used for almost any purpose, including control of any number of internal/external/virtual interfaces, control of any combination of routed traffic, setting up DMZ routers and servers, all kinds of NAT, providing strong protection (flooding, spoofing, etc.), transparent caches, source MAC verification, blacklists, and whitelists. Newer versions abstract the differences between IPv4 and IPv6, allowing you to define a common set of rules for both, while permitting specific rules for each as you need. Sanewall is a fork of FireHOL and can make use of existing FireHOL configurations.
Libporty provides a higher level API for some commonly used library functions such as sockets, date/time, file system access, background processes, and asynchronous DNS resolving. Libporty is configured using scconfig and the API is guaranteed to work the same way on all supported systems. An application that exclusively uses the libporty API will not require autotools/scconfig for porting. Libporty has been tested on Linux, Windows, Mac OS X, multiple BSD variants, Minix, OpenSolaris, and some ancient Unix systems.
Andrisoft WANSIGHT is a fully featured network traffic analyzer and collector. It provides in-depth traffic analysis, traffic accounting, and bandwidth monitoring, and enables you to generate complex traffic reports, graphs, and tops, instantly pin down the cause of network incidents, understand patterns in application performance, and make the right capacity planning decisions. It supports 10GbE packet sniffing and NetFlow, sFlow, and IPFIX.
netstat-monitor is a commandline tool for monitoring network connections. Its output is similar to the output from the netstat command with the options "netstat --inet -alp". Netstat-monitor can be left running, though, and will report new connections as they are made. Also, filters can be created to limit what's displayed to just what's unexpected or interesting.
The Interplanetary Overlay Network (ION) software distribution is an implementation of Delay-Tolerant Networking (DTN) architecture as described in Internet RFC 4838. It includes implementations of the DTN Bundle Protocol, the Licklider Transmission Protocol, and two CCSDS application protocols that have been adapted to run over the BP/LTP stack: the CCSDS File Delivery Protocol and Asynchronous Message Service.