We haven't released Tabbycat under an open-source licence, so there is no formal and general right to use this software. Nonetheless, you're welcome to use Tabbycat to help run a debating tournament if it is a not-for-profit activity. Using Tabbycat at tournaments where an individual or institution is making a profit requires our express permission. Modifying Tabbycat for profit, or using a version of Tabbycat that has been modified for profit, also requires our express permission.
If you're using Tabbycat to run a tournament we would appreciate it if you would let us know that you're doing so and how it went. Our Facebook group is a great place to do so, or you could e-mail us at the contact details in the :ref:`authors` section.
We work on this software in our spare time and make it available for not-for-profit use in the hope that it will benefit the debating community. It is provided "as is", without any warranty, and we disclaim all legal liability.