# ITK License Compatibility Concern with VNL

**URL:** https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452
**Category:** Community
**Tags:** itk
**Created:** [March 7, 2025, 2:58pm UTC](https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452 "2025-03-07T14:58:22Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![bauer-tom](https://discourse.itk.org/user_avatar/discourse.itk.org/bauer-tom/32/4483_2.png) [@bauer-tom](https://discourse.itk.org/u/bauer-tom)
#### Post date: [March 7, 2025, 2:58pm UTC](https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452/1 "2025-03-07T14:58:22Z")

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Hello,

I have noticed a potential licensing conflict in ITK related to third-party code from VNL. While ITK is distributed under the permissive Apache 2.0 license, which allows commercial use, I found that the VNL module includes a file that may not be compatible with these terms.

Specifically, the file _[rpoly.f](https://github.com/InsightSoftwareConsortium/ITK/tree/v5.4.2/Modules/ThirdParty/VNL/src/vxl/v3p/netlib/toms)_ used by Netlib, is part of the Collected Algorithms (CALGO) from ACM and is distributed under the [ACM Software License Agreement](https://www.acm.org/publications/policies/software-copyright-notice). This file was added 19 years ago to the [VNL GitHub repository](https://github.com/vxl/vxl/tree/master/v3p/netlib/toms), which appears to place it under the following licensing condition:

 ![image](https://discourse.itk.org/uploads/default/original/2X/e/e2ebc155297ac69e7dcc5749d36c921439455832.png)

Given this, it seems that ITK may not be suitable for direct commercial use. Does this interpretation seem correct? Otherwise, is there a way to compile ITK without VNL, thereby avoiding the inclusion of this file?

Thank you for your insights.

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### Author: ![dzenanz](https://discourse.itk.org/user_avatar/discourse.itk.org/dzenanz/32/1093_2.png) [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 7, 2025, 3:59pm UTC](https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452/2 "2025-03-07T15:59:56Z")

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ITK has been used for commercial purposes since its inception. I assume that approval was obtained. @hjmjohnson might know more.

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### Author: ![matt.mccormick](https://discourse.itk.org/user_avatar/discourse.itk.org/matt.mccormick/32/7_2.png) [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)
#### Post date: [March 7, 2025, 11:14pm UTC](https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452/3 "2025-03-07T23:14:52Z")

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Hello,

We were not using it, and it can be explicitly removed:

> <https://github.com/InsightSoftwareConsortium/ITK/pull/5267>
>
> These were added to VNL with the ACM Software License Agreement, which is not co…mmercial-friendly.
> 
> We were not using it, explicitly remove it.

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### Author: ![bauer-tom](https://discourse.itk.org/user_avatar/discourse.itk.org/bauer-tom/32/4483_2.png) [@bauer-tom](https://discourse.itk.org/u/bauer-tom)
#### Post date: [March 10, 2025, 11:23am UTC](https://discourse.itk.org/t/itk-license-compatibility-concern-with-vnl/7452/4 "2025-03-10T11:23:57Z")

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Hi,

Thank you very much for your prompt response and action.