xTurtle

xTurtle is built as a small and easy-to-use visual programming language that makes use of Java.

The drawing area of xTurtle includes a twenty-by-twenty square in which the turtle can move and draw.

This square has horizontal coordinates from -10 on the left to 10 on the right, and it has vertical coordinates from -10 at the bottom to 10 at the top.

Because the drawing area is unlikely to be exactly square, the coordinates for the entire drawing area probably extend beyond the range -10 to 10 in either the horizontal or vertical direction.

The turtle starts out in the center of the screen -- at the point (0,0) -- facing to the right. It can obey commands such as "forward(5)," which tells it to move forward five units, and "turn(120)," which tells it to rotate in place through an angle of 120 degrees.

The turtle can draw a line as it moves. You can think of it as dragging a pen that draws as the turtle moves.

The command "PenUp" tells the turtle to "raise the pen." While the pen is raised, the turtle will move without drawing anything. The command "PenDown" tells the turtle to lower the pen again.