"3D Fire" in 286 chars of
#GLSL!
for(float i,z,d,j;i <5e1;o =(sin(z/3. vec4(7,2,3,0)) 1.1)/d){vec3 p=z*normalize(FC.rgb*2.-r.xyy);p.z =5. cos(t);p.xz*=mat2(cos(t p.y*.5 vec4(0,33,11,0)))/max(p.y*.1 1.,.1);for(j=2.;j<15.;j/=.6)p =cos((p.yzx-vec3(t,0,0)/.1)*j t)/j;z =d=.01 abs(length(p.xz) p.y*.3-.5)/7.;}o=tanh(o/1e3);