C/Invoke is a library which can call C functions at runtime with no prior knowledge of the function prototypes. This capability is used to allow any language to call native libraries without writing a separate module in C, similar to the P/Invoke functionality of the .NET framework.
CrissCross is a small cross-platform C++ library for console and file I/O, CPU identification (CPUID), hashing (MD2, MD4, MD5, SHA-1, SHA-256, SHA-512, Tiger), sockets (TCP and UDP only currently), and data structures (LList, DArray, RedBlackTree, AVLTree, SplayTree, etc). It is designed to run on Windows, Linux, FreeBSD, OpenBSD, NetBSD, Mac OS X, and even the Nintendo DS. Other platforms may become supported upon request. The main idea is to provide the ability to write a program using identical calls on the major platforms without needing to rewrite code.
Fossil is a distributed software configuration management/version control system built with reliability and ease of use on mind. It comes with integrated bug tracking and a wiki. It is distributed as a single static binary for easy installation and the ability to run in a chrooted environment. Other highlights include a Web interface, autosync, simple networking, and CGI support.
Kannel is a WAP gateway. It attempts to provide this essential part of the WAP infrastructure freely to everyone so the market potential for WAP services, both from wireless operators and specialized service providers, will be realized as efficiently as possible. It also works as an SMS gateway for GSM networks. Almost all GSM phones can use it to send and receive SMS messages, so this is a way to serve many more clients than just those using a WAP phone. Kannel was among the first WAP gateways to be certified as WAP 1.1 compliant.