Application Enhancer (APE) is a software program released by Unsanity for Apple's Mac OS X operating system. Application Enhancer provides a framework that allows third-partydevelopers to write "haxies" for OS X. It also provides a daemon to load haxies when certain applications are launched. These haxies, or plugins, are known as application enhancer modules, or APEs. Once the APE is loaded by the daemon, the module modifies the behavior of an existing application. Examples include allowing the classic Mac OS WindowShadebehavior, or adding/removing OS X's brushed aluminum theme to all applications.
Application Enhancer is freeware, but modules may be distributed as freeware, shareware, or commercial software. A license for the Application Enhancer SDK (required by developers to deploy haxies) is $100 for shareware products and $1000 for commercial products.