Petri nets are a popular graphical way of modeling concurrent systems such as communications protocols, multiprocessor computers etc. With Petri nets it is possible to assess the correctness of systems for example by verifying that the system cannot deadlock, that there cannot be any buffer overflows etc. PIPEs main aim is to improve on existing tools available for modeling Petri Nets. A key design feature is the modular approach adopted for analysis, enabling new modules to written easily and powerfully, using built-in data layer methods for standard calculations. Six analysis modules have been written (so far) including Invariant Analysis, State-Space Analysis (deadlock, etc), Simulation Analysis & Classification. PIPE adheres to the latest XML Petri net standard (PNML). File format for saving and loading Petri-Nets is also extensible through the use of XSLT, the default being PNML. WWW: http://petri-net.sourceforge.net/