# GFortran Reference

> Independent educational publication on the Fortran programming language and scientific computing. Not part of the GNU project.

- [GFortran Reference — Independent Fortran and Scientific Computing Education](https://gfortran.org/): GFortran Reference is an independent educational publication on the Fortran language and scientific computing: getting started, numerical methods, performance, and parallel programming.
- [About GFortran Reference](https://gfortran.org/about/): GFortran Reference is an independent educational publication on the Fortran language and scientific computing, with no connection to the GNU project or any compiler vendor.
- [Contact the Editorial Team | GFortran Reference](https://gfortran.org/contact/): Contact the GFortran Reference editorial team with notes, corrections, and topic suggestions about our Fortran and scientific computing material.
- [Guides Hub | GFortran Reference](https://gfortran.org/guides/): Beginner-friendly guides from GFortran Reference on getting started with Fortran, scientific computing fundamentals, numerical methods, performance, and parallel programming.
- [Getting Started with Fortran: A Guide | GFortran Reference](https://gfortran.org/guides/getting-started-with-fortran/): A beginner guide to the Fortran language: its ISO standards history, fixed and free source form, and practical first steps for new programmers.
- [Scientific Computing Fundamentals Guide | GFortran Reference](https://gfortran.org/guides/scientific-computing-fundamentals/): A guide to scientific computing fundamentals: floating-point arithmetic, arrays as the natural data type, and how a model becomes a program.
- [Numerical Methods: An Overview Guide | GFortran Reference](https://gfortran.org/guides/numerical-methods-overview/): An overview guide to the major families of numerical methods: root finding, linear systems, interpolation, and differential equations.
- [Fortran Performance: The Basics Guide | GFortran Reference](https://gfortran.org/guides/fortran-performance-basics/): A guide to the basics of Fortran performance: what optimizing compilers do, memory and locality, and why measurement comes before optimization.
- [Parallel Programming Concepts Guide | GFortran Reference](https://gfortran.org/guides/parallel-programming-primer/): A guide to parallel programming concepts: shared and distributed memory, coarrays in the Fortran standard, and message passing.
- [Getting Started with Fortran | GFortran Reference](https://gfortran.org/getting-started/): Getting started with the Fortran language: first programs, arrays and intrinsic functions, and reading and writing files.
- [Hello World and the Basics | GFortran Reference](https://gfortran.org/getting-started/hello-world-basics/): The anatomy of a first Fortran program: the PROGRAM statement, IMPLICIT NONE, basic data types, and how programs are compiled and run in general terms.
- [Arrays and Intrinsic Functions | GFortran Reference](https://gfortran.org/getting-started/arrays-and-intrinsics/): Fortran arrays and intrinsic functions: declaring arrays, whole-array expressions, array sections, and intrinsics such as SUM, DOT_PRODUCT, and MATMUL.
- [Reading and Writing Files | GFortran Reference](https://gfortran.org/getting-started/reading-writing-files/): Basic Fortran file input and output: OPEN, READ, WRITE, CLOSE, unit numbers, formatted and unformatted records, and error checking with iostat.
- [Numerical Methods | GFortran Reference](https://gfortran.org/numerical-methods/): Numerical methods in reference style: root finding, linear systems, and ordinary differential equations, with Fortran in mind.
- [Root Finding Methods | GFortran Reference](https://gfortran.org/numerical-methods/root-finding/): Root finding methods explained: the bisection method, the Newton-Raphson method, how they converge, and how to choose between them.
- [Solving Linear Systems | GFortran Reference](https://gfortran.org/numerical-methods/linear-systems/): Solving linear systems of equations: Gaussian elimination, partial pivoting, and triangular systems, explained in reference style.
- [Ordinary Differential Equations | GFortran Reference](https://gfortran.org/numerical-methods/ordinary-differential-equations/): Numerical methods for ordinary differential equations: initial value problems, the Euler method, and the Runge-Kutta family.
- [Performance and Optimization | GFortran Reference](https://gfortran.org/performance/): Performance and optimization for scientific programs: what optimizing compilers do and a measurement-first workflow for making code faster.
- [Optimization Concepts | GFortran Reference](https://gfortran.org/performance/optimization-concepts/): What optimizing compilers do in general terms: inlining, dead code elimination, constant folding, loop transformations, and vectorization.
- [A Measurement-First Workflow | GFortran Reference](https://gfortran.org/performance/profiling-workflow/): A measurement-first workflow for program performance: timing, profiling, finding hot spots, and avoiding premature optimization.
- [Parallel Programming | GFortran Reference](https://gfortran.org/parallel-programming/): Parallel programming in reference style: coarray Fortran, a feature of the Fortran 2008 standard, and the general concepts behind message passing.
- [Coarray Fortran | GFortran Reference](https://gfortran.org/parallel-programming/coarray-fortran/): Coarray Fortran explained: images, square-bracket coarray syntax, synchronization statements, and when coarrays are a good fit.
- [Message Passing Concepts | GFortran Reference](https://gfortran.org/parallel-programming/mpi-concepts/): The general concepts behind message passing: distributed memory, ranks, point-to-point send and receive, and collective operations.
- [Resources and Quick References | GFortran Reference](https://gfortran.org/resources/): Quick-reference material from GFortran Reference, including a Fortran intrinsics quick reference for everyday programming.
- [Fortran Intrinsics Quick Reference | GFortran Reference](https://gfortran.org/resources/fortran-intrinsics-quick-reference/): A quick reference of common Fortran intrinsic functions grouped by category: numeric, array, and inquiry intrinsics.
- [Editorial Team and Standards | GFortran Reference](https://gfortran.org/editorial/): The GFortran Reference editorial team: who writes the publication, how we review and update articles, and our corrections policy.