Editing Fortran (section)

===Fortran 2003===
''Fortran 2003,'' officially published as ISO/IEC 1539-1:2004, was a major revision introducing many new features.<ref>{{cite web|title=Fortran 2003– Last Working Draft|url=http://www.j3-fortran.org/doc/year/04/04-007.txt|publisher=Gnu.Org|access-date=May 10, 2014}}</ref> A comprehensive summary of the new features of Fortran 2003 is available at the Fortran Working Group ([[ISO/IEC JTC1/SC22]]/WG5) official Web site.<ref>{{cite web |title=WG5 Completes Processing Fortran 2003 and the TR |website=nag.co.uk |date=May 14, 2004 |url=http://www.nag.co.uk/sc22wg5/ |archive-url=https://web.archive.org/web/20040805025908/http://www.nag.co.uk/sc22wg5/ |archive-date=August 5, 2004 |access-date=April 3, 2023 }}. It may also be downloaded as a PDF file at {{cite web |title=The New Features of Fortran 2003 |url=https://wg5-fortran.org/N1551-N1600/N1579.pdf |archive-url=https://web.archive.org/web/20180115012047/https://wg5-fortran.org/N1551-N1600/N1579.pdf |archive-date=January 15, 2018 |url-status=live |access-date=April 3, 2023 }}</ref>

From that article, the major enhancements for this revision include:
* Derived type enhancements: parameterized derived types, improved control of accessibility, improved structure constructors, and finalizers
* [[Object-oriented programming]] support: type extension and [[Inheritance (object-oriented programming)|inheritance]], [[Type polymorphism|polymorphism]], dynamic type allocation, and type-bound procedures, providing complete support for [[abstract data type]]s
* Data manipulation enhancements: allocatable components (incorporating TR 15581), deferred type parameters, [[volatile variable|{{code|VOLATILE}} attribute]], explicit type specification in array constructors and allocate statements, pointer enhancements, extended initialization expressions, and enhanced intrinsic procedures
* Input/output enhancements: [[Asynchronous I/O|asynchronous]] transfer, stream access, user specified transfer operations for derived types, user specified control of rounding during format conversions, named constants for preconnected units, the {{code|FLUSH}} statement, regularization of keywords, and access to error messages
* [[Function pointer|Procedure pointers]]
* Support for [[IEEE 754-2008|IEEE floating-point arithmetic]] and [[floating-point arithmetic|floating-point]] [[exception handling]] (incorporating TR 15580)
* Interoperability with the C programming language
* Support for international usage: access to [[Universal Character Set|ISO 10646]] 4-byte characters and choice of decimal or comma in numeric formatted input/output
* Enhanced integration with the host operating system: access to [[Command-line interface|command-line]] arguments, [[environment variable]]s, and processor error messages

An important supplement to Fortran 2003 was the [[International Organization for Standardization|ISO technical report]] ''TR-19767: Enhanced module facilities in Fortran.''  This report provided ''sub-modules,'' which make Fortran modules more similar to [[Modula-2]] modules.  They are similar to [[Ada (programming language)|Ada]] private child sub-units.  This allows the specification and implementation of a module to be expressed in separate program units, which improves packaging of large libraries, allows preservation of trade secrets while publishing definitive interfaces, and prevents compilation cascades.