1. This is just a User Interface for [url=http://webphysics.davidson.edu/Applets/Applets.html]Physlet[/url]. You can find the copyright from Wolfgang's Web site.
2. The interface was original created as part of editor tool for a [url=http://enjoy.phy.ntnu.edu.tw/]content management web site[/url] (However, the web site is only shown in Chinese). So teacher can use this tool to create online content or even create online assessment ...etc.  I translated this tool into English version when I was invited to the U.S. for open source physics workshop several years ago. And I added it to this forum last year. Actually, you are the first one willing to try the English version (or the first one to report the problem). So I did not work on this for a long time. But most of the functions should work fine.
I did receive the file after I click 'send to my email' button. I just added the code which will show the email address and filename been sent. You can check for the message again. It also work fine in my firefox browser. (However, it is not working when I tried it at another computer- with different Jave installed, I do not know why?).
If there are people interested in using this tool, I will try to improve it according to suggestions received.