Stock versus custom activities IMO stock activities like "email" shouldn't be treated different then activities that users supply. I would prefer one way of defining activities in jpdl4 and not begin with a set of special cases. Simplicity is something that I always hear in this forum, but IMO defining extra tags for "some" activities and a different schema for others makes it more complex and not any more simple. I think the question is where to draw the line? The way I see it, there is control flow activities and use case activities. The later would be "email somebody" or "forward the message to an ESB" type of extensions. To me it looks like being implemented as an activity is more like an implementation detail to the control flow ones and can easily be hidden behind a custom xml dialect, but the use case activities should be treated equally, regardless if they are prebuild ones, or extensions that users supply. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4161423#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...