Triangle website as seen on http://www.reddit.com/r/web_design/comments/1gficp/a_simple_website_i_made_using_processingjs_for/

Triangle-background

/start code
int mX, mY;          //global variable initialization

void setup() {       //note sure about making the screen scalable, but if you can
  size(640, 480);    //the code for drawing the triangles is parametric, so it would work
  background(200);
  noStroke();        //outlines are bad
}

void draw() {
  mX = mouseX;       //sets mX to cursor's X position
  mY = mouseY;       //sets mY to cursor's Y position
  fill(155, 111, 111, 111);
  triangle(0, height, mouseX, mouseY, width/2, height);        //draws red triangle
  fill(105, 185, 185, 111);
  triangle(width/2, height, mouseX, mouseY, width, height);    //draws blue triangle
}
//endcode