i remixed these from prof hwang's.  
Best of 2 worlds, the original university prof ones and a high school teachers remixes.
Function/Accuracy with Ease of Use/Customization high school use


could u test all 4 applets with your students and let us know what can be done to improve them.?
join in the revolution for free access to educational resources :)
anyone can join in to remix the source code and make instructional materials & worksheets to help students make sense and learn by doing.

act locally and think globally!