We hope you will enjoy our very first program written in Java. It plays a game that we discovered online and quickly became addicted to. The rules are easy: just drag the vertices around with the mouse until there are no edges crossing.
You will need to have Java enabled on your browser. If anything doesn't work or looks funny on your screen then let us know so that we can try to fix it.
Merry Christmas from Julie and Joel!
Note: Most browsers no longer support Java applets. To run Planarity as a standalone program, download and unzip Planarity.zip and double-click on the Planarity.bat file. To install Java, go to https://www.java.com/en/download/.