ML-Rules is a multi-level rule-based modeling formalism to model biochemical reaction networks. This repository contains the current version of ML-Rules supporting not only nested and attributed species, but also functions on attributes and functions on solutions. Further, ML-Rules supports arbitrary reaction kinetics. ML-Rules is implemented as an external domain-specific language using ANTLR4. Various simulators are available to execute models stochastically (using the SSA or tailored simulators), deterministically (if possible), or in a hybrid manner.