In volume I a an introduction to the algorithmic language Algol 60 was given appropriate for users of the handbook algorithms. It was pointed out that Algol fulfils a twofold function. An algorithmic language like Algol furnishes a convenient and readable means of publishing and exchanging computing algorithms; in addition, it may also be used directly for programming a modern high-speed stored-program computer, that is, for designing, testing, and using numerical algorithms. However, a modern computer can not interpret Algol programs directly. It is therefore necessary to transform the Algol statements into a form suitable for the computer. This may be done by hand or by the machine itself. For the latter case, an interpretive system for the particular machine in question is needed. In the commonly used type of system (load and run system) the source language (that is, Algol) program is handled in two stages: (1) the source language program is translated into a corresponding target (machine) language program; (2) the generated machine language program is executed. The latter program may be kept for subsequent re-execution without further reference to the translator or to the source language program.