---
title: CERN Open Hardware Licence Version 2 - Permissive
spdx-id: CERN-OHL-P-2.0
nickname: CERN OHL v2 Permissive

description: A permissive license for hardware designs, with conditions only requiring preservation of notices. Contributors provide an express grant of patent rights. Licensed works, modifications, and larger works may be distributed under different terms and without sources.

how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file.

note: 'CERN recommends (https://ohwr.org/project/cernohl/wikis/uploads/8a6b5d01f71c207c49493e4d114d61e6/cern_ohl_p_v2_howto.pdf) adding the following information in the source files: copyright and license notice, a disclaimer of warranties and a source location. You can also include the source location in a part of the design which will be visible in the end product.'

using:
  tedium: https://github.com/jboone/tedium/blob/master/LICENSE-CERN-OHL-P-v2
  LEDEAF: https://github.com/adamgreig/ledeaf/blob/master/LICENSE_CERN_OHL_P_v2.txt
  Open source controller board for ventilators: https://github.com/CV19CO/open_controller_for_ventilator/blob/master/LICENSE

permissions:
  - commercial-use
  - modifications
  - distribution
  - private-use
  - patent-use

conditions:
  - include-copyright
  - document-changes

limitations:
  - liability
  - warranty

---
CERN Open Hardware Licence Version 2 - Permissive

Preamble

CERN has developed this licence to promote collaboration among hardware
designers and to provide a legal tool which supports the freedom to use,
study, modify, share and distribute hardware designs and products based on
those designs. Version 2 of the CERN Open Hardware Licence comes in three
variants: this licence, CERN-OHL-P (permissive); and two reciprocal licences:
CERN-OHL-W (weakly reciprocal) and CERN-OHL-S (strongly reciprocal).

The CERN-OHL-P is copyright CERN 2020. Anyone is welcome to use it, in
unmodified form only.

Use of this Licence does not imply any endorsement by CERN of any Licensor or
their designs nor does it imply any involvement by CERN in their development.

1 Definitions

  1.1 'Licence' means this CERN-OHL-P.

  1.2 'Source' means information such as design materials or digital code
      which can be applied to Make or test a Product or to prepare a Product
      for use, Conveyance or sale, regardless of its medium or how it is
      expressed. It may include Notices.

  1.3 'Covered Source' means Source that is explicitly made available under
      this Licence.

  1.4 'Product' means any device, component, work or physical object, whether
      in finished or intermediate form, arising from the use, application or
      processing of Covered Source.

  1.5 'Make' means to create or configure something, whether by manufacture,
      assembly, compiling, loading or applying Covered Source or another
      Product or otherwise.

  1.6 'Notice' means copyright, acknowledgement and trademark notices,
      references to the location of any Notices, modification notices
      (subsection 3.3(b)) and all notices that refer to this Licence and to
      the disclaimer of warranties that are included in the Covered Source.

  1.7 'Licensee' or 'You' means any person exercising rights under this
      Licence.

  1.8 'Licensor' means a person who creates Source or modifies Covered Source
      and subsequently Conveys the resulting Covered Source under the terms
      and conditions of this Licence. A person may be a Licensee and a
      Licensor at the same time.

  1.9 'Convey' means to communicate to the public or distribute.

2 Applicability

  2.1 This Licence governs the use, copying, modification, Conveying of
      Covered Source and Products, and the Making of Products. By exercising
      any right granted under this Licence, You irrevocably accept these terms
      and conditions.

  2.2 This Licence is granted by the Licensor directly to You, and shall apply
      worldwide and without limitation in time.

  2.3 You shall not attempt to restrict by contract or otherwise the rights
      granted under this Licence to other Licensees.

  2.4 This Licence is not intended to restrict fair use, fair dealing, or any
      other similar right.

3 Copying, Modifying and Conveying Covered Source

  3.1 You may copy and Convey verbatim copies of Covered Source, in any
      medium, provided You retain all Notices.

  3.2 You may modify Covered Source, other than Notices.

      You may only delete Notices if they are no longer applicable to the
      corresponding Covered Source as modified by You and You may add
      additional Notices applicable to Your modifications.

  3.3 You may Convey modified Covered Source (with the effect that You shall
      also become a Licensor) provided that You:

       a) retain Notices as required in subsection 3.2; and

       b) add a Notice to the modified Covered Source stating that You have
          modified it, with the date and brief description of how You have
          modified it.

  3.4 You may Convey Covered Source or modified Covered Source under licence
      terms which differ from the terms of this Licence provided that You:

       a) comply at all times with subsection 3.3; and

       b) provide a copy of this Licence to anyone to whom You Convey Covered
          Source or modified Covered Source.


4 Making and Conveying Products

You may Make Products, and/or Convey them, provided that You ensure that the
recipient of the Product has access to any Notices applicable to the Product.


5 DISCLAIMER AND LIABILITY

  5.1 DISCLAIMER OF WARRANTY -- The Covered Source and any Products are
      provided 'as is' and any express or implied warranties, including, but
      not limited to, implied warranties of merchantability, of satisfactory
      quality, non-infringement of third party rights, and fitness for a
      particular purpose or use are disclaimed in respect of any Source or
      Product to the maximum extent permitted by law. The Licensor makes no
      representation that any Source or Product does not or will not infringe
      any patent, copyright, trade secret or other proprietary right. The
      entire risk as to the use, quality, and performance of any Source or
      Product shall be with You and not the Licensor. This disclaimer of
      warranty is an essential part of this Licence and a condition for the
      grant of any rights granted under this Licence.

  5.2 EXCLUSION AND LIMITATION OF LIABILITY -- The Licensor shall, to the
      maximum extent permitted by law, have no liability for direct, indirect,
      special, incidental, consequential, exemplary, punitive or other damages
      of any character including, without limitation, procurement of
      substitute goods or services, loss of use, data or profits, or business
      interruption, however caused and on any theory of contract, warranty,
      tort (including negligence), product liability or otherwise, arising in
      any way in relation to the Covered Source, modified Covered Source
      and/or the Making or Conveyance of a Product, even if advised of the
      possibility of such damages, and You shall hold the Licensor(s) free and
      harmless from any liability, costs, damages, fees and expenses,
      including claims by third parties, in relation to such use.


6 Patents

  6.1 Subject to the terms and conditions of this Licence, each Licensor
      hereby grants to You a perpetual, worldwide, non-exclusive, no-charge,
      royalty-free, irrevocable (except as stated in this section 6, or where
      terminated by the Licensor for cause) patent licence to Make, have Made,
      use, offer to sell, sell, import, and otherwise transfer the Covered
      Source and Products, where such licence applies only to those patent
      claims licensable by such Licensor that are necessarily infringed by
      exercising rights under the Covered Source as Conveyed by that Licensor.

  6.2 If You institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Covered
      Source or a Product constitutes direct or contributory patent
      infringement, or You seek any declaration that a patent licensed to You
      under this Licence is invalid or unenforceable then any rights granted
      to You under this Licence shall terminate as of the date such process is
      initiated.


7 General

  7.1 If any provisions of this Licence are or subsequently become invalid or
      unenforceable for any reason, the remaining provisions shall remain
      effective.

  7.2 You shall not use any of the name (including acronyms and
      abbreviations), image, or logo by which the Licensor or CERN is known,
      except where needed to comply with section 3, or where the use is
      otherwise allowed by law. Any such permitted use shall be factual and
      shall not be made so as to suggest any kind of endorsement or
      implication of involvement by the Licensor or its personnel.

  7.3 CERN may publish updated versions and variants of this Licence which it
      considers to be in the spirit of this version, but may differ in detail
      to address new problems or concerns. New versions will be published with
      a unique version number and a variant identifier specifying the variant.
      If the Licensor has specified that a given variant applies to the
      Covered Source without specifying a version, You may treat that Covered
      Source as being released under any version of the CERN-OHL with that
      variant. If no variant is specified, the Covered Source shall be treated
      as being released under CERN-OHL-S. The Licensor may also specify that
      the Covered Source is subject to a specific version of the CERN-OHL or
      any later version in which case You may apply this or any later version
      of CERN-OHL with the same variant identifier published by CERN.

  7.4 This Licence shall not be enforceable except by a Licensor acting as
      such, and third party beneficiary rights are specifically excluded.
