Wikipedia
OpenCards
OpenCards is a free spaced repetition flashcard program. The software is similar to SuperMemo, Anki or Mnemosyne.
The flashcards are saved as PowerPoint presentation files and may include text, images, sounds and LaTeX equations. The learning states are saved in hidden meta-data files in the same directory as the flashcards files. OpenCards implements learning schemes for short-term and long-term memorization.