Open BEAGLE is a fully extensible generic framework which should in principle support any kind of evolutionary computation. It also supports strongly-typed GP, Automatically Defined Functions and ephemeral random constants. The object oriented design enables one to add new components and to change the existing ones. One important version 4 change is to Open BEAGLE's high-level architecture. While this change simplifies the whole implementation, it requires users of earlier versions to invest some time in order to adapt to it. Open BEAGLE is a mature, feature-rich, well-supported framework. Obviously a lot of thought and programming effort went into its design and implementation. Out of the box, Open BEAGLE provides support for several flavors of genetic algorithms, bit-string, integer-valued vector, real-valued vector, as well as evolutionary strategies, including CMA-ES, tree-based genetic programming, co-evolution and multi-objective optimization.