Kanagram mixes up the letters of a word (creating an anagram), and you have to guess what the mixed up word is. (GPL)
Linux - FreeBSD
KLettres aims to help to learn the alphabet and then to read some syllables in different languages. (GPL)
Linux - FreeBSD
OpenTeacher is an opensource application that helps you learning a foreign language. Enter a list of words in both a known and a foreign language, and OpenTeacher tests you. (GPL)
Linux - Windows
zkanji is a free, open-source Japanese language learning tool and also a kanji and word dictionary software providing many useful features for those who are interested in the Japanese language. (CDDL)
Windows
8 applications