bpmn-js #Project#: A BPMN 2.0 rendering toolkit and web modeler.
Activiti #Project#: Helping businesses solve automation challenges in distributed, highly-scalable and cost effective infrastructures.
Camunda #Project#: Camunda BPM is a light-weight, open-source platform for Business Process Management.
Prefect #Project#: Prefect is a new workflow management system, designed for modern infrastructure and powered by the open-source Prefect Core workflow engine. Users organize Tasks into Flows, and Prefect takes care of the rest.
Apache Airflow #Project#: Airflow is a platform to programmatically author, schedule and monitor workflows.
Drools #Project#: Drools is a Business Rules Management System (BRMS) solution. It provides a core Business Rules Engine (BRE), a web authoring and rules management application (Drools Workbench) and an Eclipse IDE plugin for core development.
Easy Rules #Project#: it provides the Rule abstraction to create rules with conditions and actions, and the RulesEngine API that runs through a set of rules to evaluate conditions and execute actions.
json-rules-engine #Project#: json-rules-engine is a powerful, lightweight rules engine. Rules are composed of simple json structures, making them human readable and easy to persist.