The organization behind BIND, Kea DHCP, and related internet infrastructure software, and the namesake of a two-paragraph permissive copyright grant. Anyone may use, copy, modify, and distribute the covered code for any purpose, with or without a fee, as long as the copyright notice and this permission notice appear in all copies. Choose a License describes that grant as functionally equivalent to the Expat-style MIT text and the 2-clause Berkeley Software Distribution (BSD) grant, with language removed that is no longer necessary.
Internet Systems Consortium published the text for its own infrastructure software. The Software Package Data Exchange (SPDX) short identifier is ISC.
The permission grant
The operative sentence is a copyright permission, not an End-User License Agreement (EULA). Recipients keep the right to use, copy, modify, and redistribute without a separate clickwrap.
- Permission: Use, copy, modify, and/or distribute the software for any purpose.
- Notice: Keep the copyright notice and the permission notice in all copies.
- Fee: Distribution may be with or without a fee, so charging for copies, support, or a product that includes the code is not, by itself, a violation.
- Patents: The text is silent. There is no express patent license, unlike Apache License 2.0 (Apache).
- Copyleft: None. Derivatives may be proprietary. The GNU project lists the grant as a free-software license compatible with the GNU General Public License (GPL), so it can sit in Free and Open Source Software (FOSS) trees without a copyleft clash.
- Warranty: The software is provided “AS IS.” The author disclaims warranties, including merchantability and fitness, and limits liability for damages arising from use or performance.
SPDX records that the permission line changed from and to and/or in July 2007. The matching template treats /or as optional, so older notices still map to the same identifier.
BIND, OpenBSD, and the shorter BSD text
Internet Systems Consortium (successor to Internet Software Consortium) used this grant on the stacks that made the name familiar in network operations:
- BIND 9: Releases prior to BIND 9.11.0b shipped under this grant. Current public BIND 9 is under the Mozilla Public License 2.0 (MPL).
- ISC DHCP: Versions prior to 4.4.0 used this grant. 4.4.0 and later use MPL 2.0.
- Kea and Stork: Kea prior to 1.0.0 used this grant. Current Kea DHCP and all versions of Stork use MPL 2.0.
OpenBSD later adopted the same short form as the preferred notice for new code. Its copyright policy states the legal reason in two sentences:
The ISC copyright is functionally equivalent to a two-term BSD copyright with language removed that is made unnecessary by the Berne convention. This is the preferred license for new code incorporated into OpenBSD.
OpenBSD Copyright Policy
Compared with the MIT License and BSD-2-Clause
All three are short, permissive, and patent-silent. The practical difference is how much boilerplate sits on top of the same idea: keep the notice, disclaim warranty, and allow reuse including in closed products.
| Point | ISC | MIT License | BSD |
| Grant shape | One sentence: use, copy, modify, and/or distribute for any purpose, with or without fee | Enumerated rights, including merge, publish, sublicense, and sell | Redistribution and use in source and binary forms, with or without modification |
| Notice duty | Copyright and permission notice in all copies | Copyright and permission notice in all copies or substantial portions | Notice retained in source; reproduced with binaries |
| Express patent grant | None | None | None |
| Copyleft | None | None | None |
| SPDX identifier | ISC | MIT | BSD-2-Clause |
Teams that want an express patent license usually look to Apache License 2.0 instead. Product and platform groups still put this shorter notice on Open Source Software (OSS) libraries and Application Programming Interface (API) client kits when they want reuse, including inside proprietary products, and are willing to forgo that patent grant.