GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.
nexB OpenAssets is a tool for inventorying, managing, and monitoring applications, software, hardware, networks, and generally any IT asset. It is designed so that system administrators, IT, and finance can determine what they have, how it is configured, what it is used for, and how much it is being used, so that informed decisions can be made. It complements existing network management software, integrates with a growing number of protocols and tools, and features no-agent discovery and inventory, configuration management including dependencies and correlation, monitoring, and reporting. It makes extensive and innovative use of XML, Xpath, and Xquery.
Poslib is a library which provides easy access to the Domain Name System. The client part can be used to create DNS client applications, while the server part lets you easily create a multi-threaded DNS server program, portable to many operating systems including Linux, FreeBSD, and Windows.
RakNet is a networking API that is a wrapper for reliable UDP and higher level functionality on Windows, Linux, and Unix. It allows any application to communicate with other applications on the same computer, over a LAN, or over the internet. Although it could be used for any networked application, it was developed specifically for rapid development of online games and the addition of multiplayer to single player games.
Channel is a C++ template framework for distributed message passing and event dispatching. Its major components (message IDs, routing algorithms...) are highly configurable as template parameters. As a namespace shared by peer threads, channels support publish/subscribe scope control, message filtering, and translation.
ZooLib allows one to write a single set of C++ sources which can be compiled into native executables for Mac OS, Windows, BeOS, or POSIX-compliant systems that use the X Window system (such as Linux). Zoolib provides a GUI toolkit with a uniquely flexible layout system. It also provides a single-file database format, TCP networking, and extensive debugging support. ZooLib applications are multithreaded. ZooLib requires only minimal support from the underlying OS and platform GUI layer, and thus could be ported to a completely new platform without too much difficulty. ZooLib is fully production quality on Windows and MacOS, completely implemented but untested on BeOS, and not yet complete on POSIX. Please note that the sources from the "demo" branch are also required to build ZooLib or to get started writing your own ZooLib applications.