Stores learning data (represented as decks of cards that each have a question and an answer side) in ".mem" database files, which are interoperable with a number of other spaced repetition applications
Mnemosyne is written in Python, which allows for its use on Microsoft Windows, Linux, and Mac OS X. Users of the software usually make their own database of cards, although pre-made Mnemosyne databases are available, and it is possible to import SuperMemo collections and text files.
Each day, the software displays each card that is scheduled for repetition. The user then grades their recollection of the card's answer on a scale of 0-5. The software then schedules the next repetition of the card in accordance with the user's rating of that particular card and the database of cards as a whole. This produces an active, rather than passive, review process.
Mnemosyne voluntarily collects data from its users, and is a research project on long-term memory.
An August 2009 version of the dataset was made available via BitTorrent; a January 2014 version is available for download. Otherwise, the latest version is available from the author, Peter Bienstman, upon request.