GENIE is an international collaboration of scientists that plays the leading role in a) the development of a modern and universal event generator framework and tools in support of neutrino experiments, b) the consistent, validated and efficient implementation of a constellation of alternative physics models within a common platform, c) the development and characterisation of novel comprehensive physics models for the simulation of neutrino interactions, and d) the development of an advanced global analysis of neutrino scattering data.

The GENIE collaboration maintains a popular suite of software products (including the Generator, Comparisons, Tuning, and Reweight products) for the experimental neutrino community.

The well-known Generator implements a modern framework for Monte Carlo event generators and includes state-of-the-art physics modules. The GENIE physics model is universal and comprehensive: It handles all neutrinos and targets, and all processes relevant from MeV to PeV energy scales. The Generator includes several tools (flux drivers, detector geometry navigation drivers, and specialized event generation apps) to simulate complex experimental setups in full detail. The GENIE Generator is used by nearly all modern neutrino experiments and its predictions serve as standard reference points for the neutrino community.

The Comparisons product includes very extensive curated archives of neutrino, charged-lepton and hadron scattering data, as well as highly-developed software to produce a comprehensive set of data/MC comparisons. It includes embedded interfaces to the Professor tuning tool which "reduces the exponentially expensive process of brute-force tuning to a scaling closer to a power law in the number of parameters and allows for massive parallelisation". The Comparisons product plays a key role in comprehensive model characterization in GENIE, it underpins the GENIE global analysis, and it enabled the production of several new tunes.

The Tuning product implements the powerfull new GENIE global analysis of neutrino scattering data. The GENIE global analysis produces physics tunes which are fully integrated in the Generator product.

Finally, the Reweight product includes a selection of tools to propagate model uncertainties and to support generator-related analysis tasks. The reweighting procedure has inherent limitations. Important modelling systematics are not reweightable in principle and they have no corresponding weight calculator in the Reweight product. Indeed, the GENIE tuning procedure itself makes no use of the Reweight product but it relies on response functions constructed from brute-force parameter scans made with the aid of the Professor tool. Currently, the Reweight product it does not provide the full systematic error for any GENIE tune. However, we have medium-term plans to overhaul this product and use it for public release of the detailed Professor/YODA response functions constructed from our brute-force systematic parameter scans, as well as to release all covariance matrices from the GENIE global fits of neutrino scattering data. The upgraded Reweight product will support all public GENIE physics tunes!