The Scripting Bridge is a framework developed by Apple, Inc. in OS X allowing Mac applications to communicate with each other without the use of an intermediary scripting language such as AppleScript. Like AppleScript, the Scripting Bridge uses Apple events for inter-application communication.
The Scripting Bridge is typically used from Objective-C, but can be used in other programming languages through an Objective-C bridge such as PyObjC.
References
Scripting Bridge Wikipedia(Text) CC BY-SA