This project is a lightweight, self-contained library for gizmo editing commonly found in many game engines. It includes mechanisms for manipulating 3d position, rotation, and scale. Implemented in C++11, the library does not perform rendering directly and instead provides a per-frame buffer of world-space triangles. An included example is built on top of GLFW (with an OpenGL 3.3 context). Known limitations include hardcoded assumptions about a right-handed, Y-up coordinate system. While the gizmos are provided with vertex normals, the example does not perform any fancy shading. Furthermore, mouse-drag input with certain gizmos at extreme interaction grazing angles is known to produce anomalous output.