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
- http://www.jboss.com/products/jbpm

wftk: Open-Source Workflow Toolkit
- The wftk is a general-purpose open-source workflow engine and toolkit, designed to work with diverse interfacing systems (databases, mail systems, and user interfaces).
- http://www.vivtek.com/wftk/

Enhydra Shark
- Open Source workflow engine and client applications (admin and worklist handler) based on WfMC and OMG specification.
- http://www.enhydra.org/workflow/shark/

Enhydra JaWE - Graphical Java Workflow Process Editor
- Open source graphical workflow process editor supporting WfMC specifications. Can be used to view and edit XPDL files.
- http://www.enhydra.org/workflow/jawe/

Open Business Engine
- 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.
- http://sourceforge.net/projects/obe/

List of Open Source Workflow Projects
- Maintained by Dutch consultants Topicus. They list version, language, status and license of more than a dozen open source workflow projects, and provide a short summary of each project's focus. Owner Michiel Schipper also maintains a Blog on workflow rela
- http://www.topicus.nl/topwfm/Tooloverzicht.htm

OpenFlow Introduction
- Open source workflow engine which models activity-based workflow. Most of the information and documentation of OpenFlow is in Italian, but the English-language introduction is well-written.
- http://www.openflow.it/

CuteFlow - Document Circulation System
- Web-based document circulation tool (Open Source). Users are able to define "documents" which are sent step by step to every user in a list.
- http://sourceforge.net/projects/cuteflow

WfMOpen workflow engine
- WfMOpen is a lightweight J2EE based workflow engine with OMG like API, using XPDL as process description language. Open Source.
- http://wfmopen.sourceforge.net

OpenWFE
- Java-based open source workflow engine.
- http://www.openwfe.org