LWT - Learning with Texts, multiuser
This is a popular open source text language-learning application that's normally meant for a single user. I've set up a site to handle multiple users. They can enter in whatever text they want, define which dictionaries to use from the internet, then learn through repeated word use. There is also a flashcard utility built in.
I specialize in translation, localization and building LMS e-learning systems. I have extensive experience with Moodle, Mahara, Drupal, Joomla and Wordpress setup and maintenance for educational purposes.