Rule 30 in JavaScript

rule30.js

// you can also paste it into here: http://hello.processing.org/editor/
// (but use their `rect` function, not the one below)

function rect(x,y,w,h) {
  //console.log("rect("+x+", "+y+", "+w+", "+h+");")
  x /= 3
  y /= 6
  x = parseInt(x)
  y = parseInt(y)
  process.stdout.write("\033["+(y+1)+";"+(x+1)+"H\033[41m  \033[0m");
}

var i, j, side=6, array=[], rule=30, bits=[];

for(i = 0; i < 160; ++i) array.push(0);
array[79] = 1;

for(i = 0; i < 8; ++i) bits[i] = 1&(rule>>i);

for(i = 0; i < 40; ++i) {
  var crntRow = array.slice(39-i, 39-i+80);
  for(j = 0; j < crntRow.length; ++j)
    if(crntRow[j]) {
      rect(side*j+1, side*i+1, side, side);
      rect(side*j,   side*i,   side, side);
    }

  var nextArray = [];
  for(j = 0; j < array.length-2; ++j)
    nextArray[j] = bits[array[j]*4 + array[j+1]*2 + array[j+2]];
  array = nextArray;
}