Below is an early version of a Java program for automatically interlacing sets of shapes. This program requires Java version 1.5 (also known as 5.0) or later. If you don't see shapes below, here are instructions to update Java on your machine. You may also get a warning from your browser that it has blocked content. In that case, you can tell it to allow the content to be displayed.
Click and drag the shapes. For now, interlacing works sensibly only when no more than two shapes overlap in any one place.
Here is an installation link for the Java runtime. Look for "Java Runtime Environment (JRE)" and click the "Download JRE" below it (or "JDK" if you want to develop Java programs). Click on the "Accept" circle below the license agreement, and then the "continue" button". Then under "Windows Platform", click "Windows Online Installation, Multi-language".