In addition to MVC, GEF developers/enthusiasts need to have a good under standingunderstanding of [[Design Patterns]]. The most recurring design patterns under GEF are [[Factory method pattern|Factory]], [[Chain-of-responsibility pattern|Chain of responsibility]], [[Command pattern|Command]], [[Observer pattern|Observer]] and [[State pattern|State]]. These patterns are often mandatory under GEF, for instance EditPartFactory implementation. Certain aspects of GEF code can be correlated to these. The jargon (italicized text) is strictly GEF specific.
* Factory: Creating models from palette, creating ''editparts'' and creating figures.
* Observer: Typically a controller (read ''editpart'') listening on Model and View.
* Chain of Responsibility: To decide which ''EditPolicy'' should handle a ''Request''.
* State pattern: A typical example of which is opening editors for an input model .
