03.11.2026
We are proud to announce that, after 5 years of development and five iterative pre-releases, the ICON ComIn library has reached its first stable milestone: **ComIn version 1.0.0**. This release is bundled with the corresponding ICON Open Source Release `icon-2026-10` and is the result of a close partnership among DWD, DLR, DKRZ, FZJ, and KIT.
ICON ComIn simplifies the way researchers extend the ICON model in an easily maintainable way. As a plug-in framework, it exposes ICON’s variables, data structures, and coupler components through a unified C++ core while providing identical APIs for Python, Fortran, and C/C++. This opens the door to rapid, language-agnostic development of diagnostics, physics packages, and machine-learning tools. The plug-in framework eliminates the need for invasive code changes, allowing custom modules to be attached cleanly to the model.
With version 1.0.0, ComIn provides a foundation for a more modular and sustainable approach to Earth-system modelling. Looking ahead, we will work to maintain a stable API that enables existing plugins to continue working unchanged with future ICON versions. We invite the community to revisit the documentation and continue building on this foundation.
Users who have already developed plugins with one of the pre-release versions receive a dedicated migration guide and personal support to ease the transition to v1.0. New users are welcome to explore the application website, where a growing portfolio of real-world applications—from advanced diagnostics to innovative physics and AI integrations—demonstrates the library’s versatility. Comprehensive documentation is publicly available. Several workshops have already been held, and the next event will be the natESM Technical Training Day on 25 November in Hamburg.