FORTRAN 77
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| FORTRAN 77 | |
|---|---|
 Fortran-lang community · Public domain · source | |
| Name | FORTRAN 77 |
| Paradigm | Procedural, imperative |
| First appeared | 1978 |
| Designer | John Backus, Peter Naur, John W. Backus |
| Developer | American National Standards Institute, International Organization for Standardization |
| Latest release | 1978 standard |
| Typing | Static, weak |
| Influenced by | FORTRAN IV, FORTRAN II, FORTRAN I |
| Influenced | Fortran 90, Fortran 95, Fortran 2003, BLAS, LAPACK |
FORTRAN 77. FORTRAN 77 is a standardized version of a high-level programming language originating in the 1950s and formalized in the late 1970s by standards bodies. It provided a portable framework for numerical computation used across scientific, engineering, and commercial institutions and influenced later language designs, numerical libraries, and compiler technology. The standard balanced legacy code preservation with incremental modernizations to support structured programming and data handling.
History
The origins trace to initiatives led by John Backus at IBM and subsequent committees within American National Standards Institute and the International Organization for Standardization. Early successors such as FORTRAN IV and FORTRAN II shaped syntax and semantics that the 1978 standard consolidated. Work on the standard involved contributors from organizations including ACM, IEEE, and national bodies like BSI and DIN. Major computing centers—Los Alamos National Laboratory, Lawrence Livermore National Laboratory, CERN, and universities such as MIT, Stanford University, and University of Cambridge—adopted and ported implementations, driving interoperability needs. The standard emerged amid contemporaneous developments in languages like C, ALGOL 60, and Pascal, reflecting tensions between backward compatibility and structured-programming advocates such as Edgar Dijkstra.
Language features
The language emphasizes fixed-format source layout and concise runtime semantics adopted by compilers produced at IBM, DEC, and CDC. Numeric computation centered on real and complex arithmetic supported by intrinsic functions and array operations widely used at NASA, NOAA, and research institutes. Control structures include arithmetic IF and computed GOTO inherited from earlier dialects, while block IF and END IF constructs and statement functions provided more structured flow influenced by trends seen at Bell Labs and AT&T. Character handling and intrinsic I/O formatting allowed record-based file interaction needed by scientific data centers at Argonne National Laboratory and Brookhaven National Laboratory. Common storage and equivalence permitted low-level memory overlays, matching practices in codebases at Sandia National Laboratories and industrial firms like General Electric.
Standardization and revisions
The 1978 standard was formalized through committees tied to ANSI and international subcommittees under ISO. Revisions and technical corrigenda addressed ambiguities raised by compiler vendors such as DEC and Sun Microsystems and by users at computation-heavy organizations including IBM Research, Hewlett-Packard, and Siemens AG. Discussions in standards forums considered influences from programming language researchers like Niklaus Wirth and implementers from Cray Research and Fujitsu. Subsequent standards—most notably successors spearheaded by ISO/IEC JTC1/SC22—incorporated larger feature sets and modernization while preserving many legacy constraints to ensure code longevity across supercomputing centers such as Oak Ridge National Laboratory.
Implementations and compilers
Commercial and academic compilers proliferated, with prominent vendors releasing optimized products for architectures from mainframes to minicomputers. Notable compiler families were produced by IBM for System/370, Cray Research for vector supercomputers, and DEC for VAX systems, while vendors like Microsoft and Sun Microsystems offered implementations for workstations. Open-source and academic compilers surfaced from university projects at University of California, Berkeley and Massachusetts Institute of Technology, influencing toolchains used at Los Alamos National Laboratory and research groups at Princeton University. Numerical library ecosystems such as BLAS and LAPACK were commonly implemented in the language, and vendor-supplied optimizing compilers targeted platforms from Intel x86 to MIPS and SPARC. Debuggers and profilers integrated with development environments from Siemens AG and Hewlett-Packard supported deployment in aerospace contractors like Boeing and Lockheed Martin.
Legacy and influence
The standard shaped subsequent Fortran standards and had a lasting impact on numerical computing practices at institutions such as CERN and European Organization for Nuclear Research research groups, national laboratories, and commercial R&D labs including General Motors and Shell plc. Its conventions influenced array notation, intrinsic procedure libraries, and compiler optimization techniques that informed projects at Intel Corporation and library standards like BLAS and LAPACK. Educational curricula at Massachusetts Institute of Technology, Stanford University, and University of Oxford incorporated the language for numerical methods courses for decades, and migration paths to modern successors were developed by teams at Argonne National Laboratory and Los Alamos National Laboratory. The preservation of legacy scientific codes fostered community efforts in ports, bindings, and interoperability with languages such as C, Python, and Fortran 90, ensuring its artifacts remained central to long-term computational science projects at centers including Fermilab and JPL.