The Monad.Reader is an electronic magazine about all things Haskell. It is less formal than journal, but more enduring than a wiki-page or blog post. There have been a wide variety of articles, including: exciting code fragments, intriguing puzzles, book reviews, tutorials, and even half-baked research ideas.
Please note that the Monad.Reader has moved to http://themonadreader.wordpress.com. This site will no longer be updated.