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].
This information courtesy of the Free On-line Dictionary of Computing at www.foldoc.org.