PICI-NMS is an object oriented middleware which makes possible sending messages in a networked environment or on a single host between applications using the library provided. The supported message sending mechanism is "publish/subscribe" and this is backed up by a very easy-to-use and intuitive C++ API which hides the underlying socket interface to make the message sending as transparent to the client as possible.
Dpmaster is a lightweight master server initially written for the DarkPlaces game engine. Its Quake III Arena-like protocol allows it to fully support new games without having to restart or reconfigure it. In addition to its own protocol, dpmaster also supports the master protocols of "Quake III Arena", "Return to Castle Wolfenstein", and "Wolfenstein: Enemy Territory".
rnio is a minimalistic nio framework for Java. With rnio, it is easy to use non-blocking network sockets in Java. Internally, rnio runs a set of selectors and handles the thread pool for the network-related tasks. This means that non-blocking network connections can be fully event-based.
Herqq UPnP (HUPnP) is a software library for building UPnP devices and control points conforming to the UPnP Device Architecture version 1.1. It is designed to be simple to use and robust in operation. It is built using the Qt framework, following many of the design principles and programming practices used in the Qt framework. It integrates into Qt-based software smoothly and enables truly rapid UPnP development.
Pagekite is software to make servers on "localhost" visible to the wider Internet. It can be used by Web developers to show off their works in progress to clients or colleagues, embedded developers who need direct access to devices in the field, or as an alternative to dynamic DNS for individuals/hobbyists who would rather host their own content than rely on 3rd party hosting. It creates and maintains a tunnel between your server on localhost and a remote "front-end" (a reverse proxy). Only the front-end has to have a visible IP address; the server itself can reside on a heavily firewalled computer, a mobile device, or even an anonymous node on the Tor network.