With the first beta release of Drupal 5 now in the news, it's time for module developers to start upgrading their code to work with the new changes. The means -- of course! -- diving into the Forms API. While Drupal.org has piles of excellent documentation on the API, sometimes it's useful to keep some of the trickier bits handy for reference.
We've put together this one-page cheat sheet for Drupal 5's FormAPI: download it, print it, love it!