There's a good discussion in the Google group of the ideas that differentiate what we are now calling "classical" FBP (or CFBP) from FBP-like systems, more and more of which are appearing all the time - in particular the topic "Underlying models" - https://groups.google.com/forum/#!topic/flow-based-programmi... .

If you are interested in the more large volume, data-processing, "classical" FBP implementations, a good place to start is my book, "Flow-Based Programming", 2nd ed., and the web site http://www.jpaulmorrison.com/fbp/ .