What's New?

Here you can see what is new in various versions of CPN Tools and Access/CPN and which versions of Access/CPN works with which versions of CPN Tools. The list is not necessarily comprehensive, but lists the major changes.

The list may also reflect features in versions of CPN Tools that have not yet been publicly released, and as such reflects changes that are currently in the source repository but have not yet been deemed important enough to make a general release.

CPN Tools


  • New simulator compiled with SML/NJ 110.78 and Cygwin from February 2015



  • Make Declare constraints work with groups


  • Make Declare constraints honored during fast forward
  • Improved Declare performance after fast forward


  • Fix PNML export for arc weights and reset/inhibitor arcs
  • Handle layering correctly after closing a sheet
  • Improved printing of aux shapes created using the external API


  • Fixed wrong bounding box for printing with collapsed current marking
  • Fixed partial state-space problems with automatic progression
  • Don't start text editor on constraints


  • Fixed cloning Declare constraints
  • Fixed deleting Declare constraints
  • Fixed (disabled) interplay between Declare constraints/reset arcs/inhibitor arcs and substitution
  • Graphical improvements cloning reset/inhibitor arcs
  • Fixed bendpoints for Declare constraints
  • Fixed drawing problems when deleting Declare constraints
  • Declare constraints are now checked incrementally


  • Load/save Declare works
  • Fixed last Declare constraints
  • Option for setting memory for simulator extensions
  • NOTE: Models using Declare saved using previous versions are not compatible with this version! Such models will not be compatible with any future version.


  • Much improved support for Declare
  • Fix Rayleigh and Weibull distributions


  • Add labels from external sources
  • Model statistics (tool tip on model name in index)
  • Improved aux graphics
  • Allow extensions to add instruments
  • Re-expose ogpath and ASAP options
  • Fixed a bug causing the cursor to blink in weird ways
  • The linux simulator is back


  • Drawing primitives
  • Minimize extension server to tray
  • On-demand activation of extensions


  • Support for intinf and time color sets
  • Experimental support for real color sets. Please read this page before using this or asking for support!!


  • More intuitive load/save from palette
  • Save net as PNML:

  • Automatic snap to grid
  • Remove guide grid and place kinds


  • More control over simulation options for fast forward simulation (total number of steps, end time)
  • Added the Weibull distribution.
  • Time-equivalence reduction for state space analysis.
  • Ranges supported for time stamps (using extensions):

  • No longer fails if extensions are not started.


  • ONLY USE THIS VERSON TO TEST SIMULATOR EXTENSIONS It does not yet gracefully degrade if you don't! You will not be able to create nets without extensions, and extensions are not yet optimized, making this version seem significantly slower.
  • Preliminary support for simulator extensions:



  • Graphical tweaks (for port places, arcs, binders + sheets, background)
  • Improved support for working with low-level nets; demo:

  • Preliminary support for DRAWING inhibitor + reset arcs
  • Preliminary support for DRAWING ordered + bounded places

3.4, 3.2, 3.0


Next Version

  • Fix for exporting nets of depth > 2 (thanks to Robert Kranz for the fix)


  • Improved handling of monitors
  • Better handling of starting simulator; should work in packaged jars and Eclipse workspaces on all platforms.
  • Update for CPN Tools 3.4.0


  • Minor change to textual representation of page instances


  • Update for CPN Tools 3.3.1


  • Update for CPN Tools 3.3.0


  • Vastly improved exporter to CPN Tools (thanks in part to Dirk Fahland)
  • Support for loading and checking monitors (EXPERIMENTAL)


  • Update to be compatible with CPN Tools 3.2.2.
  • Facilitate synchronization on Execution Context.
  • Improved handling of (integer) time during cosimulation.
  • Better support for loading while not connected to the internet (thanks to Stephan Schweig)
  • Better support for running from source (thanks to Stephan Schweig)
  • Improved export to .cpn files (including automatic layout if desired)





  • Initial Release. Automatically grade many CPN models against one specification. Also logic-based testing of CPN models.