Create your own course to memorize anything you want. Flashcard-based, with formatting and images, with multiple flashcard types. Spaced-repetition app, focused on ease and speed of creating own courses, with flashcard formatting (LaTeX, image insertion) and cloze deletion flashcards. Spaced-repetition site, created with these points in mind:

• advanced flashcard formatting (LaTeX formulas, code syntax highlighting, image insertion, html-like formatting)
• speed of creating and learning courses, fast slick interface
• 2 types of flashcards: cloze-deletion flashcards (when one word is missing, and you have to insert it when reviewing the flashcard) - best for learning languages; and question-answer flashcards - best for science/programming/maths/any subject that needs an extended answer. Additional features:
• it's completely free and open-source, you are welcome to contribute, reports bugs, and request new futures, response is momentary.
• site uses an SM2 algorithm for flashcard-repetition depending on your answers (same as Brainscape and Memrise). Is you answer your flashcards perfectly well, the repetition frequency will be approximately: 4 hours, 1 day, 4 days, 8 days, 13 days, 19 days, 25 days, 32 days, 41 days, etc.
• it's possible to navigate the interface completely via the keyboard.