Thanks Julian, the Playpen is a fantastic resource and it is really useful to see and test the different filters in action on Moodle 1.9 alpha.
One minor typo re the Jmol filter. It should be DNA not DNS (you have been around computers too long ).
Now teaching has stopped, I'm hoping to update both the Jmol Filter and Jmol Resource type over the summer. Dan Stowell, who did most of the original coding for these, is currently 'otherwise engaged' in his PhD studies.
In the meantime, and if you have a little spare time, you may wish to update the Jmol components in the /filter/jmol folder to the latest stable version (11.2.4 at the current time) on your installation. Amongst other improvements, the Jmol applet has recently been broken down into a set of smaller components which are only used 'on demand'. This should improve the Jmol applet performance.
So you will need to replace any existing xxx.js and and xxx.jar files with the new versions of jmol.js, jmolApplet0.jar and ALL other files of type jmolApplet0_xxx.jar (the 'signed' versions are NOT required). A bit fiddly, but hopefully worth it.
Keep up the good work!
PS. You can easily check the Jmol version by right clicking on the applet and selecting 'About Jmol' from the bottom of the menu. You will also probably have to clear your browser cache to 'see' any update of the applet.