Binary compatibility

• “An ABI is an "application binary interface" and describes binary-level conventions for applications running on a particular system. An ABI establishes conventions for such things as register usage, parameter passing, and layout of data. Typically, these conventions are embodied in development tools, particularly compilers.”

• http://developer.apple.com/tools/mpw-tools/compilers/docs/abi.html

• In contrast, languages like Java and Python run on virtual machines/interpreters that abstract away these differences between platforms.