Xj3D is an open-source Java codebase for the X3D Graphics standard.
SDL with native XInput
Vivid3D is a C++ IDE/3D engine, with python scripting.
High-efficiency minimalist C++ wrapper for OpenGL 4.3
A simple 3D framework in C++
CIRT - CUDA Interactive Ray Tracer
3D Model Viewer and Converter
Realtime raytracer using SIMD on ARM, MIPS, PPC and x86
C++ Frontend for the RenderMan Interface
crossplatform multithreaded object-oriented render and audio engine
Java3d scenegraph editor
C++ header-only library that simulates GLSL math
realistic driving simulation + functions for 2D/3D graphics
Interactive 3D Layout Viewer for GDSII
3D Without Boundaries
Server-side rendering and prerendering for Angular
Vue.js components rendering 3D WebGL graphics reactively with three.js