partial support for Fortran 2003 (more information available on request).support for C, C++, FORTRAN 77, Fortran 90/95.licensed under the Open Source CDDL license.Version 1.3.1 is a fully functioning API. This release includes updates to the make system, bug fixes, better support of CYGWIN systems, portability improvements, and a fix in order to work with gnu make 3.81. By conforming to this API, an atomistic simulation code will seamlessly work with any KIM-compliant interatomic model written in any supported language. The KIM development team is pleased to announce the release of version 1.3.1 of the KIM application programming interface (API).