A simple HTML+JavaScript page to convert between different 3D rotation formats, quaternions, Rodrigues angles, Euler angles, etc.
Run hosted website directly to convert rotations online
Most of the conversion is calculated with the three.js library (which is also MIT-licensed).
Permissive MIT license, see file LICENSE
To generate the minified math part of three.js, call
python three.js-master/utils/build/build.py --include math --minify --output three-onlymath.min.js