The following code produces different results with OPENGL and P3D (version 0089). The P3D looks as expected, but OPENGL will just show a blank canvas.

Additional oddity: In P3D it works correctly, but ortho() automagically centers the world coords around the top left corner of the window. Maybe that's supposed to happen, what do I know.

Code:

import processing.opengl.*;

void setup() {
  size(1066,200, P3D);
  framerate(5);
}

void draw() {
  background(200);
  lights();
  ortho(0,width, 0,height, -10,20);

  translate(width/2,height/2);
  for(int i=0; i<10; i++) {
    pushMatrix();
    translate(random(width),random(height));
    rotateX(PI/4);
    rotateY(PI/4);
    box(50);
    popMatrix();
  }
  
} 

That's what I thought too, but it maps values in the range (-width/2,-height/2) to (width/2,height/2), hence the translate in the code to bring it back on the screen.

I was just testing ortho() to see if it was an alternative to perspective rendering since the aspect ratio of my canvas is so extreme that perspective yields correct but weird effects. So it's not a big priority, I'm sure there are more important bugs to fix.

filed in the bugs db:
http://dev.processing.org/bugs/show_bug.cgi?id=100
closing thread.