Activiti

Activiti is an open-source Java-based BPMN workflow and process automation platform. It provides a light-weight engine for executing BPMN 2.0 process definitions and automating business processes within Java applications and microservices. It exposes a Java API and REST API to deploy process definitions, start process instances, manage tasks, and query history.

The core components include the process engine, a runtime repository, a task service, and a history service. Process definitions are authored in BPMN 2.0 and stored in a repository; at runtime the engine coordinates activity execution, timers, events, and user or service tasks. The platform supports human tasks via task lists and forms, and basic decision support via DMN in newer releases. It can be embedded into Spring-based applications and is commonly used with Spring Boot.

Activiti provides a web-based modeler for BPMN diagrams and a monitoring interface to inspect process instances, tasks, and audit trails. It offers RESTful and Java APIs, enabling external applications to start processes, signal events, and query task status. The platform is designed to run on premise or in the cloud and supports clustering for scalable deployments.

Activiti has an active community and ecosystem, with ongoing development under an open-source license (Apache-style). It has influenced related BPM engines and competitors, such as Flowable and Camunda, which originated from early Activiti work. The project supports cloud-native extensions in Activiti Cloud for microservices architectures.

Typical use cases include automated approvals, order processing, and incident response workflows that require traceability and human involvement. For more information, see the official Activiti project site and community documentation.