If you are interested in getting Calico running in a language other than English, or if you would like to get students involved in a computer science project through an alternative approach, this information may be relative to you.
Currently, Calico is written a manner to use translations through the "gettext" system. All strings in the main Calico program have been marked for version 2.2.8 (and greater), and exported to the calico.pot, on-line here:
Locally, the locale folder is in the Calico folder that you would download.
The calico.pot file is copied to language files (such as es.po and fr.po, for Spanish and French, respectively) in that same folder. Those po files are then compiled to .mo files.
You also need the Gtk language files on your operating system. On Linux, those can be installed through the language-packs (eg, sudo apt-get install language-pack-es).
Once that has been done, you would run Calico, like this (on Linux and Mac):
On Windows, one can edit the StartCalico.bat file (see the .bat file for examples).
Changing the LANGUAGE environment variable should result in Calico running in your the identified language. (If you see a word or phrase that is not translated, that is a bug.)
There are many tools for editing .po files. Currently, there are versions for Spansh (es), French, (fr) and Chinese (ch). All of those could use editing by native speakers.
If you have questions, please don't hesitate to ask.