Towards an implementation of Co-Array Fortran. There is a good chance that Co-Array Fortran (of which one can find a description here: ftp://ftp.nag.co.uk/sc22wg5/N1651-N1700/N1677.pdf) will be included in the Fortran 2008 Standard. From the article cited above: "A Fortran program containing co-arrays is interpreted as if it were replicated a fixed number of times and all copies were executed asynchronously. Each copy has its own set of data objects and is called an image. The array syntax of Fortran is extended with additional trailing subscripts in square brackets to give a clear and straightforward representation of access to data on other images." I will describe the steps that have to be undertaken to make GNU Fortran capable of compiling Fortran programs using co-arrays. This includes enhancements to the parser, the intermediate description of programs in the Fortran Front End and the necessary support of the run-time library. The request for a Co-Array Fortran implementation in GNU Fortran is an old one: It is the subject of PR 18918 and dates from the 10th of December 2004, 4 months before the release of GCC 4.0, the first with the current GNU Fortran compiler. Although a full implementation - capable of compiling Fortran codes for distributed memory systems - is challenging, an implementation that caters for run-of-the-mill quad-core shared memory PC's that sell for ~ $ 1000 would immediately be useful.