Flow-based Programming

Panta rhei (Panta rhei) - Everything flows.

In computer programming, Flow-Based Programming (FBP) is a programming paradigm that uses a "data factory" metaphor for designing and building applications. FBP defines applications as networks of "black box" processes, which exchange data across predefined connections by message passing, where the connections are specified externally to the processes. These black box processes can be reconnected endlessly to form different applications without having to be changed internally. FBP is thus naturally component-oriented.

FBP is a particular form of dataflow programming based on bounded buffers, information packets with defined lifetimes, named ports, and separate definition of connections.

Video Interview with J. Paul Rodker Morrison, Summer 2013

If you have come across Flow-Based Programming by way of NoFlo or Flowhub, it is recommended that you read Relationship with NoFlo, which attempts to highlight the differences and similarities between what we are now starting to refer to as "classical" FBP (the subject of this web site), on the one hand, and NoFlo and other similar FBP-like systems on the other. "Classical" FBP involves a significant paradigm shift for the majority of programmers, and so may seem harder to grasp than NoFlo and its relatives, but our experience suggests that making the effort to shift the application development paradigm is well worth the effort, as it promises more maintainable and understandable applications, better communication between applications designers, programmers, users and systems people, as well as improved performance for jobs involving large data volumes. FBP also lends itself to rapid prototyping, unit testing of components, plus easy addition and removal of "monitoring" components.

We know you are tired of Powerpoint presentations, but this one (from 2007) gives quite a good overview of FBP - as it was at that time. It's worth taking a look!


  1. Introduction
  2. History
  3. Concepts
  4. Software:

  5. Examples
  6. Comparison with other paradigms and methodologies
  7. Relationship with NoFlo
  8. Bibliography
  9. Chapters from the first edition - online
  10. External links

Google group on Flow-Based Programming

Link to Flow-Based Programming Wiki

Twitter hashtag: #FlowBased