Fountain 3D is a little J2ME toy and a technology demo for a custom-made 3D wireframe engine with some benchmarking abilities thrown in. The camera is fully controllable by the user together with the simple particle simulation. The software doesn't require hardware acceleration; all J2ME compliant mobiles are supported.
Fraqtive is a multi-platform generator of the Mandelbrot family fractals. It uses very fast algorithms that support SSE2 and multi-core processors. It generates high quality anti-aliased images and renders 3D scenes using OpenGL. It allows real-time navigation and dynamic generation of the Julia fractal preview.
FreeSG is a portable, high-level 3D engine with an emphasis on generality. It is designed as a component to be integrated, as opposed to an application framework. Its goal is to support applications ranging from small 3D games running on portable consoles to large simulations that must be rendered photorealistically using fourth-generation graphics hardware.
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.
GL2PS is a C library providing high quality vector output for any OpenGL application. It uses sorting algorithms capable of handling intersecting and stretched polygons, as well as non manifold objects. It provides advanced smooth shading and text rendering, culling of invisible primitives, mixed vector/bitmap output, and much more. It can currently create PostScript (PS), Encapsulated PostScript (EPS), Portable Document Format (PDF), and Scalable Vector Graphics (SVG) files, as well as LaTeX files for the text fragments.