The High Performance ParalleX (HPX) library has produced its 0.9.5 release. Here's a snippet about HPX from its release announcement.

[...] HPX (High Performance ParalleX) is a general C++ runtime system for parallel and distributed applications of any scale. It is the first freely available, open source, feature-complete, modular, and performance oriented implementation of the ParalleX execution model. HPX is targeted at conventional architectures and, currently, Linux based systems, such as SMP nodes and conventional clusters. [...]