Open Business Engine
- http://sourceforge.net/projects/obe/
- Open source workflow engine written in Java, designed to execute workflow definitions written in XPDL. Designed to be embedded in an application, used as a stand-alone server, or used in a J2EE container.
ProcessMaker
- http://www.processmaker.com
- Open source business process management software suite for SMEs that automates custom document-intensive, approval-based processes.
YAWL
- http://www.yawlfoundation.org
- An open-source workflow engine with a fully-featured workflow modelling environment and execution engine.
jBpm
- http://www.jboss.com/products/jbpm
- Open Source workflow management system based on J2EE. It runs on a JBoss application server and is available under the Lesser General Public License (LGPL). Contains project description, system documentation and links to the source code. Maintained by Tom Baeyens.