Google Blockly Visual Programming Language

Blockly is a visual programming language with a web interface. Creating a program is done by connecting blocks.



Some demos:
Maze - use Blockly to go through the maze.
Code - Export a Blockly program to JavaScript, Dart, Python, or XML.

Blockly is currently in technology preview mode. All developers are invited to play around and express their ideas.



After exporting to JavaScript:

var n;
var A;
var i;
var x;
var j;
n = 100;
A = [];
for (i = 0; i <= n; i++) {
  A[i - 1] = true;
}
var i_end = Math.sqrt(n);
for (i = 2; i <= i_end; i++) {
  if (A[i - 1] == true) {
    j = Math.pow(i, 2);
    while (j <= n) {
      A[j - 1] = false;
      j = (j || 0) + i;
    }
  }
}
for (x = 2; x <= n; x++) {
  window.alert([x,': ',A[x - 1]].join(''));
}