OpenIFS

"The ECMWF OpenIFS programme provides an easy-to-use, exportable version of the IFS in use at ECMWF for operational weather forecasting. The programme aims to develop and promote research, teaching and training on numerical weather prediction (NWP) and NWP-related topics with academic and research institutions.

Use of OpenIFS on topics of interest to the Centre and member states is encouraged. Research topics at ECMWF are described in more detail on the main ECMWF site. Enquiries regarding potential collaborations are welcome.

OpenIFS provides the forecast-only capability of IFS (no data assimilation), stays close to operational version and supports operational configurations. For more details see how OpenIFS compares with IFS.
OpenIFS is supported by a small team at ECMWF for technical & scientific assistance, however, there are limited resources for detailed scientific help.

The OpenIFS model 'package' includes not just the model itself but acceptability tests for compilers/hardware, example case studies, plotting & analysis tools and so on. The model is intended for research and educational use by Universities,  research organisations and individual researchers on their own computer systems. It is not provided for any real-time forecasting. ECMWF does not provide facilities to run OpenIFS on its computer systems.

Documentation, install instructions, frequently asked questions and other help information can all be found on this website. User forums are also available. Support is provided for a range of hardware platforms and compilers.

Please note that OpenIFS is licensed software and not open-source nor in the public domain. Licenses are free of charge and typically granted as site licenses."

https://software.ecmwf.int/wiki/display/OIFS/OpenIFS+Home