The **gl‑blend‑demo** repository provides a small, ready‑to‑run WebGL example that shows how different blending modes affect an image over a background. It exports a function that creates a canvas with a configurable shader (or shader‑factory) and WebGL context, then lets developers render the demo, swap shaders, or embed the canvas in a page – making it useful for graphics programmers, shader authors, and anyone needing a quick visual testbed for blend operations.