Desktop flashcards software

I need a desktop flashcards software program that is similar to [login to view URL] I don't need all of the advanced features and statistics, but there is a 'space repetition' feature which is useful. (where you rank each flashcard on a scale of 1-5 based on how well you know it, so the flashcard is repeated with more or less frequency) We want a basic flashcards application with some of the features. It should work on windows computers (mac not really necessary at this time) It needs to be secure, because we are selling the flashcards, and we want to put some features in place to limit distribution of the flashcards. We have the flashcards info already in text files, and maybe we'll create a flashcards file format just for this program. If you can program this type of software, have any questions, or would like to discuss this, please post a bid. Please tell meany ideas you may have as well. Thanks.