Concurrent programming libraries

C++ programming library

MPICH, formerly known as MPICH2, is a freely available, portable implementation of MPI, a standard for message-passing for distributed-memory applications used in parallel computing. MPICH is Free and open source software with some public domain components that were developed by a US governmental organisation, and is available for most flavours of Unix-like OS (including Linux and Mac OS X).

ZeroMQ (also spelled ØMQ, 0MQ or ZMQ) is an asynchronous messaging library, aimed at use in distributed or concurrent applications. It provides a message queue, but unlike message-oriented middleware, a ZeroMQ system can run without a dedicated message broker; the zero in the name is for "zero broker". The library's API is designed to resemble Berkeley sockets.

Eclipse Vert.x is a polyglot event-driven application framework that runs on the Java virtual machine.

distributed task queue

.NET managed concurrency library