While a wealth of open source licenses exist for Open Source Software (OSS), the new field of Open Source Hardware (OSHW) is still lacking as many licenses. When looking at licenses for OSHW, especially when comparing a license to one from OSS, it is important to note hardware is typically covered by patents. Software, on the other hand, is typically covered by copyright, and so falls under a different legal system. Thus, with OSHW being a mix of the hardware and software to run it, it is often covered by a mix of both copyright and patentable parts. For parts of the design process, this requires that those parts not covered by copyright need a license that acknowledges that - one dedicated for hardware.

Unfortunately, many people are still using software licenses for their open hardware projects. Most notably, the MIT and GPL licenses have been reused frequently across open hardware projects such as Opencores (LGPL), FreeCores (GPL), and the Open Graphics Project (MIT, GPL, and proprietary). These projects will theoretically not have much legal recourse if their designs get patented, made/sold, or used in a closed system. Many people are using public works licenses such Creative Commons.

Limitations of OSS Licenses as applied to OSHW

There are currently no OSI approved Open Hardware Licenses. Someone started to triage all of the things needed to be done to get an open hardware license approved by the OSI, but gave up on the project. This thread is available at

Below is an attempt to capture all of the open hardware licenses available:

OSHW Definition
The Open Source Hardware Definition attempts to do for OSHW what the Open Source Initiative Definition did for Open Source Software, which is provide a strict definition for what is and isn't OSHW. While it is not a license in and of itself, it does provide a guideline for determining whether a license does or does not meet the requirement to be called Open Source. Some of the key items a licenses required to be defined as OSHW under this are:

  • Complete Documentation of Hardware
  • Complete Design Files (in an open format when available)
  • Scope of License
  • Necessary Software that is Licensed by an OSI-approved license
  • Modifications Require ‘Equal or Lesser’ Licenses
  • Optional Required Attribution
  • Freely Distributed


OSHW Definition Conforming Licenses

TAPR is the OSHW licenses that served as a guideline during the creation of the Open Hardware Definition. TAPR is based off the OSS GNU GPL License, while addressing specifically the fact that open hardware is covered by a different legal system (patents vs copyright). As such, it forbids any other license from preventing the same rights to copy and modify documentation and the make and use the product made using that documentation. There are concerns about legal edge cases, however, as there is insufficient discussion of the distribution terms.


Hardware Design Public License
The HDPL, like the TAPR License, is also one of the licenses that preceded and inspired the Open Source Hardware Definition. It is also inspired by the OSS GNU GPL. It addresses many of the same issues, with a good number of comments included to make clear the terms of the agreement. HDPL attempts to create a more comprehensive license than TAPR, encompassing legal edge-cases and a variety of hardware types, with clear definitions of terms.


Non-OSHW Definition Conforming Licenses

Chumby HDK
The Chumby HDK was developed for the Chumby, a consumer electronics device 'internet appliance'. The Chumby does not meet the requirements of the Open Source Hardware Definition, as it does not publish the original schematics, all software source code, etc. What the license does do, however, is provide a maker-friendly license that allows for modification free from 'harassment from manufacturers'. As part of this agreement, it also gives guarantee to Chumby that all modifications made to the device are made with a non-exclusive rights agreement for chumby to use.


Balloon License
The Balloon License comes from the development of the Balloon, an OSHW development board. The Balloon License does not folllow the Open Source Hardware Definition. While the PCB layouts, etc are provided free of charge and free to modify, the original design files are not provided. In short, you can manufacture the device free of charge, but not make original edits to the device without having to re-make the original design files (those used to create the PCB layout). The license focuses on the hardware aspect of the board, and does not include any software developed.


Creative Commons
The Creative Commons licesnse was originally created to cover works covered by copyright . As such, it does not cover some aspects of hardware (schematics, etc). However, it does cover board masks and documentation associated with the hardware. The works and its derivatives are freely distributed, with the only requirements being attribution to the original author(s). The Creative Commons license is, however, used in lieu of other open hardware licenses in popular OSHW projects, such as the Arduino.


Extra Resources:

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