This site is built on the open-source web architecture originally created by Earendil. The static site generator, WebGL rendering pipeline, adaptive quality system, and post-processing shader framework are derived from their work.
The background effect is based on the "Base warp fBM" shader by trinketMage, available on Shadertoy. The shader uses warped Fractional Brownian Motion with a custom colormap to produce the flowing, organic pattern you see behind the content.