ISC license

Short description: Permissive free software license published by the Internet Software Consortium

ISC license

Publisher	Internet Systems Consortium
DFSG compatible	Yes
FSF approved	Yes
OSI approved	Yes
GPL compatible	Yes
Copyleft	No
Linking from code with a different license	Yes
Website	{{{1}}}

The ISC license is a permissive free software license published by the Internet Software Consortium, now called Internet Systems Consortium (ISC). It is functionally equivalent to the simplified BSD and MIT licenses, but without language deemed unnecessary following the Berne Convention.

Originally used for ISC software such as BIND and dig, it has become the preferred license for contributions to OpenBSD and the default license for npm packages. The ISC license is also used for Linux wireless drivers contributed by Qualcomm Atheros, as well as by the LV2 plugin system.

License terms

ISC License

Copyright <YEAR> <OWNER>

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

When initially released, the license did not include the term "and/or", which was changed from "and" by ISC in 2007. Paul Vixie stated on the BIND mailing list that the ISC license started using the term "and/or" to avoid controversy similar to the events surrounding the University of Washington's refusal to allow distribution of the Pine email software. Both versions of the license are compatible with the GNU GPL.

OpenBSD license

The OpenBSD project began using the ISC license in 2003, before ISC added the term "and/or".

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Theo de Raadt of OpenBSD chose to retain the original wording, stating that he "disagrees with what ISC did" and is "not confident that their change is good".

Reception

In 2015, ISC announced they would release their Kea DHCP Software under the Mozilla Public License 2.0, stating, "There is no longer a good reason for ISC to have its own license, separate from everything else". They also preferred a copyleft license, stating, "If a company uses our software but improves it, we really want those improvements to go back into the master source". Throughout the following years, they re-licensed all ISC-hosted software, including BIND in 2016 and ISC DHCP Server in 2017.

The Publications Office of the European Union advises using the MIT license instead of the ISC License in order to reduce license proliferation.

The GNU project states the inclusion of "and/or" still allows the license to be interpreted as prohibiting distribution of modified versions. Although they state there is no reason to avoid software released under this license, they advise against using the license to keep the problematic language from causing trouble in the future.

See also

• Comparison of free and open-source software licenses

External links

• Internet Systems Consortium's License Text
• License template at the Open Source Initiative