NGinn.BPM is a workflow engine for Microsoft.Net. It employs a process modeling language similar to BPMN in key concepts and a Petri-net based process execution engine.

The main design objectives of this project are:

• Ligtweight

  Easy to embed in any kind of application, without too many external dependencies, bloat controlled tightly

• Transactional, bulletproof

  ACID properties for long running processes (data durability, atomic updates, consistency in case of failures, general reliability and robustness)

• Expressive like BPMN

  One of goals here is full BPMN support, but we concentrate on process definitions being concise, human-readable and human-authorable (without using code generators)

• Powerful and extensible

  So it can take care of many aspects of application logic, not only the process flow.

• Performant

  We pay great attention to I/O and memory efficiency of the engine

• Operation modes

  NGinn.BPM can be embedded in applications or can run as a standalone service. Processes can be run in persistent mode (intermediate state stored in database) or in memory only. Synchronous and asynchronous execution is supported (to the extent allowed by process model).

• Process model elements

  Almost all constructs known in BPMN can be modeled in NGinn.BPM. Process description language is text based and process model is serializable to JSON and XML. BPMN translation will be implemented.

• Data model

  The data model is an element of process definition. Data structures, validation rules and binding rules are defined in the model and enforced during process execution.

• SQL Server backend

  By default NGinn.BPM uses SQL Server backend, but it can be easily ported to other SQL databases.

• GUI Designer

  

  Process model will be fully editable in the designer GUI. Designer is web based, embeddable in applications. Process diagram visualization and editor are based on brilliant JointJS library. Currently it's a work in progress.

• ESB backend

  NGinn.BPM is built on top of asynchronous and transactional message bus which is a central mechanism for event-based communication between NGinn.BPM processes and application components.

Most important features yet to be implemented

• BPMN support. A tool that will translate BPMN/XPDL process description into NGinn.BPM process definition language

• GUI process designer. It should be possible to use one of free BPMN editors to define or customize processes in NGinn.BPM

• Integration interfaces - automatically generated SOAP/Web services and RESTful http interfaces for interacting with running processes

• Monitoring and management APIs for controlling process execution and performing common maintenance tasks

• Standard library of process components, eg sending and receiving email or SMS messages, common set of integration tools for popular corporate software (MS Exchange, Active Directory, LDAP, ERPs etc)

• YAWL [http://www.yawlfoundation.org/] - Petri-net based process description language with lots of research behind it. Very valuable project, I like YAWL for its simplicity and expresiveness.
• BPMN [http://www.bpmn.org/] - just what the acronym says, business process modelling notation / standard from OMG, industry standard for graphical process description. Quite complex if you go into details, but based on same concepts as YAWL and NGinn.BPM
• jBPM [http://www.jbpm.org/] - Open-source, java-based BPMN engine, process editor (and lots of other stuff), developed by RedHat. Big and complex project (inspiration to stay lean/lightweight) but has some nice features.