License comparison
MIT vs ISC: notice wording
The practical release checklist is similar: both allow commercial use and modification without copyleft, and both require copyright and permission notices. Their wording differs. MIT names copies or substantial portions of the software, while ISC requires the notices in all copies. Keep each component's actual text in your release notices rather than replacing one with the other because the licenses look alike.
Compare the permissions, limits and obligations recorded in each guide. Read the license text for the full conditions that apply to your release.
Permissions
MIT
Commercial use
You may ship the code inside a paid product. The license does not restrict commercial use.
Modify
You may change the code, including keeping those changes private, unless a later obligation says otherwise.
Distribute
You may give copies to others. Distribution is what usually turns notice and source duties into real work.
Sublicense
You may include the code under your own product terms, so long as you still meet this license's conditions.
Private use
Use inside your company, including internal forks, does not by itself trigger distribution duties.
ISC
Commercial use
You may ship the code inside a paid product. The license does not restrict commercial use.
Modify
You may change the code, including keeping those changes private, unless a later obligation says otherwise.
Distribute
You may give copies to others. Distribution is what usually turns notice and source duties into real work.
Sublicense
You may include the code under your own product terms, so long as you still meet this license's conditions.
Private use
Use inside your company, including internal forks, does not by itself trigger distribution duties.
Limits
MIT
Hold liable
The authors disclaim warranty. Recipients cannot hold them liable for damages arising from the software, except where law forbids that disclaimer.
Use trademark
The license is not a trademark license. Names, logos and product marks stay with their owners unless a separate grant says otherwise.
Patent grant
The text does not grant patents. If buyers want an express patent grant, Apache-2.0 is the usual alternative.
ISC
Hold liable
The authors disclaim warranty. Recipients cannot hold them liable for damages arising from the software, except where law forbids that disclaimer.
Use trademark
The license is not a trademark license. Names, logos and product marks stay with their owners unless a separate grant says otherwise.
Patent grant
The text does not grant patents. If buyers want an express patent grant, Apache-2.0 is the usual alternative.
Obligations
MIT
Include copyright
Keep the copyright line with every copy or substantial portion you distribute.
Include license
Keep the license text with every copy or substantial portion you distribute. A web page is not a substitute for notices inside a shipped artifact.
Substantial portion
MIT names copies or substantial portions. Keep the copyright line and the permission notice with both whole packages and excerpts you vendor.
ISC
Include copyright
Keep the copyright line with every copy or substantial portion you distribute.
Include license
Keep the license text with every copy or substantial portion you distribute. A web page is not a substitute for notices inside a shipped artifact.
All copies
ISC asks that the copyright notice and the permission notice appear in all copies. It does not use MIT's substantial-portion phrasing.
License texts
Practical guidance for procurement review, not legal advice. Confirm high-stakes use with counsel.