BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
Ayam is a free 3D modelling environment for the RenderMan interface. It features good RIB export, CSG (all RenderMan primitives supported), and NURBS modelling. Features instancing, arbitrary number of modeling views, object clipboard, independent property clipboard, n-level undo, console, and Tree-View with Drag-and-Drop support.
Agar is a toolkit for graphical applications. It features a modern GUI system with an unobtrusive API. Agar can use different graphics interfaces, such as SDL and OpenGL, and it has been ported to numerous platforms, including game consoles and embedded systems. Agar is implemented in C, but can be used from other languages.
G3D is a C++ library for game developers, researchers, and students. It is a base of robust and high performance code common to most 3D projects. It is not a stand-alone graphics or game engine, but is a set of pieces to jump start your own engine or graphics project. The library has two parts: G3D for pure math, and GLG3D for interacting with hardware acceleration via OpenGL. You can use G3D without GLG3D if you want to use another 3D API (like DirectX) or don't like the OpenGL abstraction.
Esdl is library for accessing SDL and OpenGL through Erlang. SDL handles 2d graphics, user events, and audio while OpenGL handles 3d graphics. SDL (Simple DirectMedia Layer) is a cross-platform multimedia library designed to provide fast access to the graphics framebuffer and audio device. It also does event handling from mouse, keyboards, and joysticks. OpenGL is a cross-platform standard for 3D rendering and 3D hardware acceleration.
Brook for GPUs is a compiler and runtime implementation of the Brook stream programming language for modern graphics hardware. The goals for this project are to demonstrate general purpose programing on GPUs, to provide a useful tool for developers who want to run applications on GPUs, and to research the stream language programming model, streaming applications, and system implementations.