Orkid is a flexible media presentation engine. By media, we mean games, realtime 2d/3d graphics, and/or audio. Orkid itself is licensed with the permissive Boost Software License v1.0, that said Orkid does have dependencies on other libraries which will have different licenses and it is left up to the user to remain compliant with them. Orkid, being fairly modular can be run with less dependencies and reduced functionality to simplify license creep.

Some Features Include:

• Built in multiplatform asset management.
• Batch conversion system (asset filters), I suppose its similar to assimp.
• Built in Scene/Object Editor.
• Data Driven Design.
• Entity/Component based scene/simulation system.
• External references of character archetypes for sharing across scenes.
• Generic Dataflow modeling primitives used for modular audio synthesis, modular particle systems and modular terrain synthesis .
• Flexible simulation architecture does not to dictate game/simulation policy, but does provide tools to help with implementation.
• Game-Genre agnostic..
• Integrated Bullet Physics Engine.
• HlslFx/CgFx/GlslFx shader based renderer.
• Fixed Function and Node based compositing engine with offline rendering mode (dumps to image files on disk).
• QT4.8/OpenGL based UI
• Many more...

for other examples of content, go here and here

Osx: http://www.tweakoz.com/orkid/OrkidTool.dmg (includes LGPL licensed Qt4.8)