ISC License (ISC)
Functionally equivalent to MIT/BSD-2.
Key facts
- SPDX id
- ISC
- Category
- Permissive
- Copyleft scope
- none
- Express patent grant
- No
- SaaS triggers disclosure
- No
- GPL-compatible
- Yes — compatible with the GPL.
Obligations
When redistributing as open source.
- ISC: retain the copyright notice and license text.
Commercial use
Yes. Commercial use is permitted; retain the copyright notice and license text.
- ISC: retain the copyright notice and license text.
Permissive: include notices (Apache also needs NOTICE + change statements). Weak copyleft: disclose only the modified library/files and, for LGPL static linking, provide a relink path. Strong copyleft (GPL): NOT possible to keep proprietary if GPL code is in the derivative work. AGPL: same as GPL plus network rules.
FAQ
- Can I use ISC in a commercial product?
- Yes. Commercial use is permitted; retain the copyright notice and license text.
- Do I have to open-source my code if I use ISC?
- No. ISC never requires you to disclose your source.
- Does running ISC software as a SaaS require source disclosure?
- No. Hosting is not distribution under ISC; running it as a service does not trigger source disclosure.
- Is ISC compatible with the GPL?
- Yes — compatible with the GPL.
Compatibility with other licenses
- Is ISC compatible with MIT? Yes
- Is BSD-2-Clause compatible with ISC? Yes
- Is BSD-3-Clause compatible with ISC? Yes
- Is Apache-2.0 compatible with ISC? Yes
- Is BSL-1.0 compatible with ISC? Yes
- Is ISC compatible with Unlicense? Yes
- Is CC0-1.0 compatible with ISC? Yes
- Is ISC compatible with MPL-2.0? Yes
- Is EPL-2.0 compatible with ISC? Yes
- Is ISC compatible with LGPL-2.1? Yes
- Is ISC compatible with LGPL-3.0? Yes
- Is GPL-2.0-only compatible with ISC? Yes
- Is GPL-2.0-or-later compatible with ISC? Yes
- Is GPL-3.0-only compatible with ISC? Yes
- Is AGPL-3.0 compatible with ISC? Yes