Fireworm: Eye candy with the gradient drawing tools of the canvas tag (no direct image writing) and a little bitmapped logo coded into 30 characters of ASCII (6 pixels a char, eh!) And thanks to Peter…
var A="QsdbfCQUeRjDQweJnD_@DV`DQ@|b`D",B=Math.sin,C=Math.cos,E=6,F="rgba(",G,I,J,K=16,L,M,N,O=function(n){return Math.floor(n*128+128)},P=160,Q="0,0,0,",S=",",U;s=function(){D=(C(E/121)*5)+3;L("source-over");I.fillStyle=F+Q+((B(E/K)+2)/5)+")";I.fillRect(0,0,P*2,P*2);for(k=5;k--;){for(j=36;j--;){n=Math.pow(2,j%6);if((A.charCodeAt(k*6+Math.floor(j/6))-64)&n){x=8+j*4;y=k*4+K*B(j/K+E)+K;M();I.moveTo(x,y);I.lineTo(x,6+y);I.stroke();N();}}}L("lighter");for(i=K;i--;){j=(E+i*D*4)/P*((D+6)/4);x=C(j+B(j*2))*2+B(C(11+j*3))*P+P;y=B(j*5)-C(7+j*9)*P+P;z=B(11*x/K)*64+96;G=I.createRadialGradient(x,y,0,x,y,z);g=C(x*(E/P)/K);h=g*j/K;G.addColorStop(0,F+O(C(h))+S+O(g)+S+O(B(h))+",.6)");G.addColorStop(1,F+Q+"0)");I.fillStyle=G;M();I.arc(x,y,z,0,Math.PI*2,false);I.fill();N();}E+=1/8;};U=document.getElementById('c');I=U.getContext("2d");U.width=320;U.height=320;I.strokeStyle=F+Q+"1)";I.lineWidth=5;L=function(a){I.globalCompositeOperation=a};M=function(){I.beginPath()};N=function(){I.closePath()};J=setInterval(s,30);
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
Original source not submitted