Release It! - 17.3 Enabling Technologies

A black-box technology sits outside the process, examining it through externally observable things. Black-box technologies can be implemented after the system is delivered, usually by operations. White-box technology runs inside the thing being observed—either a process or a whole system. The system deliberately exposes itself through these tools. These must be integrated during development. White-box technologies necessarily have tighter coupling to the system than black-box technologies.  JMX is an example of a White-box technology.