When the original Smalltalk-80 "blue book" came out in 1983, it included a complete listing of a reference implementation of the virtual machine. http://sdmeta

When the original Smalltalk-80 "blue book" came out in 1983, it included a complete listing of a reference implementation of the virtual machine. http://sdmeta.gforge.inria.fr/FreeBooks/BlueBook/ http://sdmeta.gforge.inria.fr/FreeBooks/BlueBook/ Instead of using Pascal or C, the code was written in a subset of Smalltalk-80 itself. This subset (later named Slang in the Squeak project in 1996) doesn't use objects nor polymorphism. It only deals with an Array of integers and only uses a few control structures, so every expression has a C equivalent. The first VM implementers at Apple, DEC, Tektronix and HP manually translated this code into Pascal, assembly or C as their starting point and then evolved their code from there. Much later it was shown that this code could actually run inside Smalltalk-80. http://ftp.squeak.org/docs/OOPSLA.Squeak.html http://ftp.squeak.org/docs/OOPSLA.Squeak.html