Machine independence

A survey is offered of techniques for transferring programs, and especially compilers, from one computer to another. Of the methods examined, the "bootstrap" technique is singled out for detailed discussion, with emphasis on its economics. The considerations that determine the applicability of bootstrapping in any specific case are discussed, and an attempt is made to assign appropriate qualitative weights to them. Finally, reasons are given for believing that the machine-lndependence proMem is being substantially diminished by current trends in computer design, and that it is this process of convergence in hardware design rather than any foreseeable software developments that will lead to its satisfactory resolution.