Entity/Component System for C++
'entity' implements a method to compose object-like things from component-like things in a dynamic, yet typesafe fashion. Such a system is usually refered to as en Entity-Component system. Several interesting properties can come from such a design such as increased performance, reduced memory usage, looser coupling and cleaner code.
Incomplete, but evolving, documentation is available here.
GCC/Clang (Travis-CI):
MSVC (Appveyor):