A virtual machine implementation approach, used to speed up execution of byte-code programs. To execute a program unit such as a method or a function, the virtual machine compiles its bytecodes into (hardware) machine code. The translated code is also placed in a cache, so that next time that unit's machine code can be executed immediately, without repeating the translation.
This technique was pioneered by the commercial Smalltalk implementation currently known as VisualWorks, in the early 1980s. Currently it is also used by some implementations of the Java Virtual Machine under the name JIT (Just In Time compilation).
[Peter L. Deutsch and Alan Schiffman. "Efficient Implementation of the Smalltalk-80 System", 11th Annual Symposium on Principles of Programming Languages, Jan 1984, pp. 297-302].