CirclePack operates mainly through "scripts". Click Menagerie as an example. The script will appear in the "Script" window; you can click through using "NEXT" for a quick tour.
I created and maintain CirclePack for purposes of my own mathematical research, so it is always a "beta" version and subject to change. However, to better share this fascinating topic, I have tried to make CirclePack as user-friendly, capable, and stable as possible. I enjoy hearing about related mathematical questions, about applications or potential applications, and about the software. Feel free to join the open forum (just being initiated) or contact me directly. Enjoy!
Ken Stephenson (Knoxville, Tennessee, August 11, 2012)