FORTRAN has always been intended to be an efficient high-level language, and its adherence to this original design aim has helped it to achieve a dominant position in scientific, engineering and other areas of computing. However, advice on how to obtain the best possible performance has, until now, been scattered through the literature, in brief articles, detailed reports on specific computers, and very general and often superficial chapters in books on FORTRAN programming.**This book, for the first time, deals with the whole topic in a systematic fashion, and every effort has been taken to include only the most up-to-date information, and to present it in a way which clearly distinguishes between the different techniques required for the various types of compiler.**The book begins with an extensive introduction to the subject, including a justification for optimizing, explanations of the hardware of modern computers, and the optimizing techniques used by FORTRAN 77 compilers. The preparatory work required before optimizing begins is covered, followed by a detailed discussion of the procedures which may be applied to source code to achieve the highest efficiency of execution, according to the type of compiler used. IBM and CDC compilers are covered in detail. Program portability is discussed and the use of super-computers introduced. The plans for future FORTRAN are presented. A widely used layout-program appears in an appendix.**FROM THE PREFACE: Throughout its more than two decades of history, one of FORTRAN's main strengths as a programming language has been its adherence to its original design aim of providing efficient program execution. However, advice on how to obtain the best possible performance has hitherto been scattered, being contained either in reports on specific computers and compilers (e.g. Smith et al., 1977), or in parts of various books of rather too general a nature. This book brings together for the first time a detailed survey of the means by which FORTRAN source code may be optimized, and includes other background information which should enable the reader to understand better how a FORTRAN program is processed by a compiler, and subsequently executed. As such, it is intended to help all those who write or run FORTRAN programs to make efficient use of computer resources without making unjustifiably great demands on their own time.**This book should be useful as a reference work for anyone engaged in FORTRAN programming on any scale greater than simple, single-shot, short jobs, and as a supplementary text in any course on FORTRAN programming beyond the preliminary stages.