Drupal Context Module Abridged

"The Context module is developed by the Washington DC Drupal shop Development Seed. It is one solution to the Drupal problem of using multiple pieces of code scattered throughout a site asking questions such as "Is an event node being displayed?", "Is a view of events being displayed?", or "Is an event form being displayed?" Context enables a single piece of functionality that asks "Is the events section being displayed?" This can be incredibly useful to control active menu trails, block visibility, and theme layouts and classes.

A context becomes active if one or more conditions are met (see below for a full list of conditions). If a context becomes active it will cause one or more reactions. A simple context example is to react by displaying the recent comments block in the sidebar region if the condition of viewing a story node type is met."