The Jmol filter retains hard-coded text strings in many places. These need to be replaced with internationalised lang files and variables.
Szymon Kalasz has already done a good job on this as part of GSOC 2008.
However, this has not yet been merged into the Jmol Filter release code
If the lang file architecture is put in place, hopefully the community will come up with the translations
The Jmol applet itself has fully internationalised menus, so this should make the job easier for the Moodle integration.