I always wondered why an Nginx module that was about generating a circle had such prominence on the Nginx website and now I can say I understand =]<p>Although this was premature optimization I still find it a beautiful hack. The author was still not content with the C solution of actually generating the GIF each time (which took 30ms, actually a long time for servers) and instead reframed the problem at a deeper level and created a beautiful little hack that just modified the palette table.