conexus is a generalized C++ I/O library that includes network support for IPv4 and IPv6 sockets, serial/TTY communications, kernel message queues, pipes, and files. Objects use sigc++ for signaling property changes and other information. Sub-libraries include conexus-gtkmm (provides a set of gtkmm widgets), conexus-dbus (provides dbus support for endpoints), conexus-nspr (provides NSPR endpoints), conexus-nss (provides NSS endpoints), and conexus-ssl (provides OpenSSL endpoints).
Collage is a cross-platform C++ library for building heterogenous, distributed applications. Among other things, it is the cluster backend for the Equalizer parallel rendering framework. It provides an abstraction of different network connections, peer-to-peer messaging, node discovery, synchronization, and high-performance, object-oriented, versioned data distribution. It is designed for low-overhead multi-threaded execution, which allows applications to easily exploit multi-core architectures.