Hi, Just a small post, it might clarify more of the BL. The inheritance structure of the BL of Piper looks like this: data <-- data that nodes transport | node <-- node layer, the core of the system | | relation | <-- Handles relations between node, also the conflicts | | | legacy <- legacy code, OS\hardware specific stuff | | resource <- Handles resources (ram, hd space, etc.) | area <-- all above this (data->resource) is private, but accessible | through wrappers | engine <- few public functions for the admin layer | | | admin <- external interfaces to engine, may be GUI or scripts | plugin <- nodes in BL are implemented by plugins | | | | | visual <- plugins of type visual, cq output nodes | | | filter <- plugins of type filter, cq internal nodes | sensor <- plugins of type sensor, cq input nodes Maybe somebody has some feedback about it. It looks like the right structure so far, the BL core already runs based on this. I'm now doing the DL and PL code. (Both BL plugins) jarl