MontyLingua is a popular Natural Language processing tool which can understand english language and also correct it based on common sense – used by many people around the world for research. It did have a small problem – licensing.

The author released it under two licenses which states that:

If it is your intent to use this software for non-commercial,
non-prioprietary purposes, such as for academic research purposes,
this software is free and is covered under the GNU GPL License,
given here: <> and in the
APPENDIX of this document.

If you are interested in this software for commercial purposes,
commercial licensing information is available.  Please email
( for more information.

In my previous company, we have been trying to reach the author for the commercial license but he hasn’t replied to any emails. So we decided to make use of another NLP tool and move on. But a few days back there was a discussion in Reddit where it was noted that someone can get the software for non-commercial use under GPL – which gives him the full right offered by GPL. So he can copy, modify and share the software to anyone and the person who gets the software from him (not Hugo) can get it under GPL. This essentially avoids the commercial license path of MontyLingua Version 2.0 license.

I thought since I was already working on improving the code, why don’t I fork it, do the bug fixes and release it under GPL. This will allow anyone else to come up and fix the code and improve the project. Since the author isn’t actively working on this project, I think using this fork will benefit everyone to get a better version.

I have created a public repository in bitbucket called MontyLingua3 (the old one is in version 2.1). Right now I am going to clean up the code and since I am not a NLP expert there won’t be any new additional features. If someone can contribute with new features/functions then I would be very happy to include their patches.

To get the source code, install mercurial and clone the repository as

$ hg clone

So, please contribute to the project. If you are interested to discuss about Software Licensing, especially open source licenses, do ping me.