ISC considering a change to the BIND 9 license

ISC published BIND under a very permissive open source license nearly two decades ago. Since then, it has become the world’s most widely used nameserver. Partly, this is due to the popularity of commercial services and software based on BIND. While this is welcome, and these commercial products are undoubtedly adding value, unfortunately not all of these users are giving back to the open source – either by contributing code or supporting the core team financially.

This is unfair to those organizations that are sustaining the open source BIND, a significant and valuable community asset. ISC is the organizational steward for BIND; in order to preserve the software for the long term, we are considering a move to the more restrictive Mozilla Public License (MPL 2.0). (read about it at tl;dr Legal

The MPL license requires that anyone redistributing the code who has changed it must publish their changes (or pay for an exception to the license). It doesn’t impact anyone who is using the software without redistributing it, nor anyone redistributing it without changes - so most users will not see any change.

In the event we do proceed with the change in license, it will take effect with the BIND 9.11.0 release.

We welcome comments from BIND users, including statements of support or concern. Email Vicky Risk, Product Manager at, tweet at us at @ISCdotORG, or discuss on

Jeff Osborn, President of ISC, announcing we are considering this change at RIPE72 in Copenhagen May 26th:

Image of a circular process, titled 'Multiple Ways to Contribute,' with 'users,' 'contributions,' 'core project,' and 'open source' in colored blocks

Recent Posts

What's New from ISC

Previous post: The ISC Performance Lab