Hi Koen, just the person I was hoping to hear from :) I will give the custom element and xml adapter approach a try, and will let you know if I run into any serious issues. My plan is to implement a workflow editor that supports our own DSL, that is basically a slightly modified version of jPDL with some new node types (so not exactly rocket science, while things are never as easy as planned...). I'm positively surprised by the new GD design, as I haven't needed to make any significant changes to org.jbpm.gd.jpdl so far (other than a few tweeks, posted as bug reports, and that hopefully may eventually become part of gd/gd.jpdl). John View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4046018#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...