Integrative landscape functioning has become a common concept in environmental management. Landscapes arecomplex systems where many processes interact in time and space. In agro-ecosystems, these processes are mainlyphysical processes, including hydrological-processes, biological processes and human activities. Modelling suchsystems requires an interdisciplinary approach, coupling models coming from different disciplines, developed bydifferent teams.In order to support collaborative works, involving many models coupled in time and space for integrativesimulations, an open software modelling platform is a relevant answer.OpenFLUID is an open source software platform for modelling landscape functioning, mainly focused onspatial fluxes. It provides an advanced object-oriented architecture allowing to i) couple models developed denovo or from existing source code, and which are dynamically plugged to the platform, ii) represent landscapesas hierarchical graphs, taking into account multi-scale, spatial heterogeneities and landscape objects connectivity,iii) run and explore simulations in many ways : using the OpenFLUID software interfaces for users (commandline interface, graphical user interface), or using external applications such as GNU R through the providedROpenFLUID package.OpenFLUID is developed in C++ and relies on open source libraries only (Boost, libXML2, GLib/GTK,OGR/GDAL, . . . ). For modelers and developers, OpenFLUID provides a dedicated environment for modeldevelopment, which is based on an open source toolchain, including the Eclipse editor, the GCC compiler and theCMake build system.OpenFLUID is distributed under the GPLv3 open source license, with a special exception allowing to plug existingmodels licensed under any license. It is clearly in the spirit of sharing knowledge and favouring collaboration in acommunity of modelers.OpenFLUID has been involved in many research applications, such as modelling of hydrological networktransfer, diagnosis and prediction of water quality taking into account human activities, study of the effect ofspatial organization on hydrological fluxes, modelling of surface-subsurface water exchanges, . . .At LISAH research unit, OpenFLUID is the supporting development platform of the MHYDAS model, which is adistributed model for agrosystems (Moussa et al., 2002, Hydrological Processes, 16, 393-412).OpenFLUID web site : http://www.openfluid-project.org