emacs-wiki.el has its own page: EmacsWiki
I've been trying to teach myself Japanese. I found flashcard.el available on the internet, and made some modifications to it. It doesn't seem to be actively maintained. I basically fixed a few bugs introduced by recent emacs versions, added support to check your answers (it used to ask you to confirm if you were right or not), and sped up advancement to the next question if you got the previous one right.
Download: flashcard.el
Emacs, Gnus & ERC configuration files