It looks like the WIRIS editor is commercial, however. The DragMath editor is part of core.
I did discover this page at the Java docs because DragMath was getting blocked for being unsigned. The solution which worked for me (and needs to be done by every user who wants to use DragMath to create.. not view.. equations) is this:
Steps to Add URLs to the Exception Site list
·Go to the Java Control Panel (On Windows Click Start and then Configure Java)
·Click on the Security tab
·Click on the Edit Site List button
·Click Add in the
Exception Site List window
·Click in the empty field under the
Location field to enter the URL
(URL should begin with http:// or https://)
If the URL where the applet is hosted is different from the URL of the web page from which the applet is launched, then you will need to add both the URL for the applet as well as the URL for the web page.