OSG composer was designed to unleash the potential of OSG developers and users. It facilitates the creation of simple to complex 3D scenes, which combine geometries from different sources. It lets you add models from different sources, place them visually using the draggers, use advanced Snap tools, add 3D text to your scene, add texture coordinates to the models, duplicate and create instances of geometries in the scene, automatically pack your scenes with all its textures in a zip file so you can share it with other users, and fix problematic models and bring them back to life.
OCE (OpenCascade Community Edition) is a community version of the OpenCascade Technology 3D kernel, a C++ library for 3D CAD development. It includes components for 3D surface and solid BRep modeling, visualization, data exchange (STEP, IGES), and rapid application development. OCE aims to fix bugs and improve code quality and portability.