LICENSE.txt

grammar is released under the AGPL (Affero General Public License) version 3 with extra conditions:

Derivative works of this software must not be used to generate content for distribution, unless there is an offer to provide the source code.
In other words, if you use this software to publish material on a social network, you must provide a download to the source code on your profile of that social network.

All derivative works containing a modified version of this project must be licensed under this license.
Derivative works containing an unmodified version of this project must be licensed under the AGPL license or a compatible license.

Contact me (the author) for clarifications or if this license is too restrictive for your purposes.