This first volume contains a complete description of standard programming language Fortran 90, covering all of its features in a format that is easier to read than the standard itself. It uses the terminology and basic organization of the standard to make it easy to use documents. The book also includes: A chart of command changes from FORTRAN 77 TO FORTRAN 90. Cross referencing of commands for typical applications from FORTRAN 77 to FORTRAN 90; Hundreds of examples of common usage of FORTRAN 90.