SIMBL short for SIMple Bundle Loader, formerly Smart InputManager Bundle Loader.
SIMBL is an application enhancement (InputManager bundle) loader for Mac OS X developed by Mike Solomon. It helps third-party developers modify and add functionality to applications developed with the Cocoa environment without access to the source code. SIMBL
loads code via the InputManager system, which was developed to support foreign input methods. Plugins using SIMBL have advantages over normal InputManager modifications such as targeted code loading into specific applications. Designed for Solomon's PithHelmet, SIMBL
is now used by other developers.