Activiti is a light-weight workflow and Business Process Management (BPM) Platform targeted at business people, developers and system admins. Its core is a super-fast and rock-solid BPMN 2 process engine for Java. It's open-source and distributed under the Apache license. Activiti runs in any Java application, on a server, on a cluster or in the cloud. It integrates perfectly with Spring, it is extremely lightweight and based on simple concepts.
Bonita is an Open Source Business Process Management (BPM) software and Workflow software edited by the BPM company BonitaSoft. Develop process based applications easily with Bonita Open Solution.
OpenLexicon is an open-source business rules and process management tool that rapidly develops applications for transaction and process-based applications. OpenLexicon is known for providing high performance solutions and has been used in a number of enterprise-level applications. You can read about these here . You can use either product separately or in concert. There are two main components of OpenLexicon: the metadata repository and the business rules engine. Major components of OpenLexicon are released as open source software under the OpenLexicon OpenSource License. A good overview of the business rules approach is available here .OpenLexicon has a Wizard that is a web-form based collaborative tool for building business rules and business use cases. For a brief overview of the wizard, look at this link . We have designed the Wizard for non-developers and analysts with light technical skills. It features a richer experience for the users on the web, traditionally only offered by thick-client UIs. The collaboration team assembles groups of business rules into a business use case and published in a metadata file or the database. OpenLexicon provides solid support for web services. You can read about the OpenLexicon WSDL here . There is also an eclipse plug-in for web services here . You create complex application behavior with OpenLexicon’s process management. OpenLexicon can build an application reads data from a file, performs reference data lookups, validates the entire object, and then stores it in a database table. You can read about this here . Plus, you can build the application in the Wizard while writing no code! OpenLexicon also supports web services. A simple architecture diagram for OpenLexicon is included here .