libsockmux-glib is an implementation of the sockmux protocol, using GIO data types and using glib functions internally. The interface offered to applications is very simple and straightforward. sockmux specifies a simple way for muxing messages and data streams onto a single socket for network and local communication streams.
OnPosix is a tiny library to abstract POSIX mechanisms to C++ developers. Most features offered by this library can be found either inside the Boost library or in a library compliant with the C++11 standard. Unfortunately, however, for some embedded Linux devices, these libraries cannot represent viable solutions, due to the lack of memory space (for the Boost libraries) and the lack of a new C++ compiler (e.g., on Xilinx MicroBlaze). On these platforms, the OnPosix library represents a good and cheap solution to have object-oriented POSIX mechanisms. The library offers support for threads, mutual exclusion, sockets, logging, timing, etc.
s6-networking is a collection of small Unix tools designed to help networking. It includes clock synchronization, Unix and TCP super-servers, Unix and TCP access control, and other miscellaneous utilities. It is particularly suited for management of clients and servers on embedded devices, but works just as well on larger systems.