The Bloxel Engine
June 2011 - Present
Website: http://www.youtube.com/bloxelengine

     Bloxel is a voxel engine mainly written in C++ with extensions available for all .NET languages (C#, Visual Basic, C++/CLI, etc.). The engine can utilize a host of algorithms to perform the mesh extraction from voxel data, from complex algorithms like Marching Cubes and Dual Contouring to basic cube extraction algorithms. Bloxel is very flexible; although the core engine is written in C++ and uses DirectX as a renderer, the renderer can be swapped out (i.e. with OpenGL, XNA, SharpDX, etc.), and the engine can be accessed from any language, provided that bindings exist. The engine is currently in its third major release, and is under heavy development.

Github - Open Source