CHSM
Concurrent Hierarchical State Machine

License

By default, the CHSM software is under the terms of the GNU General Public License (GPL). "CHSM software" includes everything in the distribution: the source files, compilers, and the run-time libraries.

What follows neither extends or restricts the terms of the GPL. What follows are mere clarifications of the GPL (since many people seem to get confused by it).

You can use the GPL and pay nothing for CHSM only if either:

  1. Your program is also under the GPL.
  2. Your program is not under the GPL and you do not distribute your program outside your company, i.e., you use your program in-house only.

The original authors of a program under the GPL (as we are with CHSM) can grant as many separate and different licenses as they please.

Hence, if your program is not under the GPL and you want to distribute your program outside your company, then you need to purchase a separate commercial license for CHSM.

In a nutshell, a commercial license for CHSM will allow you to:

To negotiate a commercial license and for pricing, please contact us.


  1. If you distribute CHSM as open-source, with or without your program, regardless of how your program is distributed, then CHSM itself reverts to being under the GPL for its recipients.
  2. You can only distribute any part of any version of CHSM released up to one year from the date of purchase forever. Example: if you purchase a license for version 4.0, you can distribute it, or any later version, e.g., 4.1, 4.2, etc., that is released within one year, forever. But if version 5.0 is released at least one year and one day after the date of purchase, then you will need a new license to distribute that or any later version.

Copyright © 1996-2013 by Paul J. Lucas and Fabio Riccardi.
CHSM is available under the terms of the GNU General Public License. Commercial licenses are also available.
Last updated: July 2, 2013