* Obviously, you may use reaction rules to react upon any event with custom conditions and actions. * Allows functionality to be re-used via components (Drupal 6: Rule sets only). * Flexible scheduling system that allows scheduling any component / action. * Users can share their customizations by using the built-in import/export feature. For that the module also integrates with Features. * Modular input evaluation system - for example you can install the Token module and use it in every action. * The module has been developed with site performance in mind, so it makes use of caching routines to speed up rule evaluation. * Rules 2.x (Drupal 7 only) features improved APIs, a new admin UI, support for all entity types, parameter configuration via simple data selection (i.e. just pass node:author as argument) and much more.