Inferno 4th Edition is available under a `dual licence' scheme.
You can choose between two licence structures:
Which licence should I choose?
The Free Software Scheme
Inferno available as `Free Software'
(in the sense of the Free Software Foundation).
Under this scheme, each subcomponent of the system is licensed under a
Free Software licence that seemed (to us) appropriate for that subcomponent.
The licences are all existing Free Software licences, not one of our own,
including GNU General Public License (GPL), GNU Lesser General Public License (LGPL),
MIT-template, Lucent Public License 1.02, and FreeType.
You can use Inferno under this scheme if the use you make of any given component will be
compatible with its Free Software licence.
This scheme replaces our own `Liberal Source Licence' used for some earlier distributions.
Commercial Developer Licence
If the result of your work using Inferno will not or cannot be made Free Software,
you can obtain the system under a more conventional commercial software licence.
This usually requires payment of a licence fee, but subsequent use (subject to the licence) is royalty free.
If you distribute Inferno with changes or additions to sections of Inferno that
are under GPL or LGPL, and you will distribute (or otherwise make available) the source code to those changes or additions,
you can choose the Free Software Scheme, otherwise choose the Commercial Developer Licence.