Open-source hardware (OSH) consists of physical artifacts of technology designed and offered by the open-design movement . Both free and open-source software (FOSS) and open-source hardware are created by this open-source culture movement and apply a like concept to a variety of components. It is sometimes, thus, referred to as FOSH (free and open-source hardware). The term usually means that information about the hardware is easily discerned so that others can make it – coupling it closely to the maker movement. Hardware design (i.e. mechanical drawings, schematics, bills of material, PCB layout data, HDL source code and integrated circuit layout data), in addition to the software that drives the hardware, are all released under free/libre terms. The original sharer gains feedback and potentially improvements on the design from the FOSH community. There is now significant evidence that such sharing can drive a high return on investment for the scientific community.
Since the rise of reconfigurable programmable logic devices, sharing of logic designs has been a form of open-source hardware. Instead of the schematics, hardware description language (HDL) code is shared. HDL descriptions are commonly used to set up system-on-a-chip systems either in field-programmable gate arrays (FPGA) or directly in application-specific integrated circuit (ASIC) designs. HDL modules, when distributed, are called semiconductor intellectual property cores, also known as IP cores.
Open-source hardware also helps alleviate the issue of proprietary device drivers for the free and open-source software community, however, it is not a pre-requisite for it, and should not be confused with the concept of open documentation for proprietary hardware, which is already sufficient for writing FLOSS device drivers and complete operating systems. The difference between the two concepts is that OSH includes both the instructions on how to replicate the hardware itself as well as the information on communication protocols that the software (usually in the form of device drivers) must use in order to communicate with the hardware (often called register documentation, or open documentation for hardware), whereas open-source-friendly proprietary hardware would only include the latter without including the former.
The first hardware focused "open source" activities were started around 1997 by Bruce Perens, creator of the Open Source Definition, co-founder of the Open Source Initiative, and a ham radio operator. He launched the Open Hardware Certification Program, which had the goal of allowing hardware manufacturers to self-certify their products as open.
Shortly after the launch of the Open Hardware Certification Program, David Freeman announced the Open Hardware Specification Project (OHSpec), another attempt at licensing hardware components whose interfaces are available publicly and of creating an entirely new computing platform as an alternative to proprietary computing systems. In early 1999, Sepehr Kiani, Ryan Vallance and Samir Nayfeh joined efforts to apply the open-source philosophy to machine design applications. Together they established the Open Design Foundation (ODF) as a non-profit corporation and set out to develop an Open Design Definition. But most of these activities faded out after a few years.
By the mid 2000s open-source hardware again became a hub of activity due to the emergence of several major open-source hardware projects and companies, such as OpenCores, RepRap (3D printing), Arduino, Adafruit and SparkFun. In 2007, Perens reactivated the openhardware.org website.
Following the Open Graphics Project, an effort to design, implement, and manufacture a free and open 3D graphics chip set and reference graphics card, Timothy Miller suggested the creation of an organization to safeguard the interests of the Open Graphics Project community. Thus, Patrick McNamara founded the Open Hardware Foundation (OHF) in 2007.
The Tucson Amateur Packet Radio Corporation (TAPR), founded in 1982 as a non-profit organization of amateur radio operators with the goals of supporting R&D efforts in the area of amateur digital communications, created in 2007 the first open hardware license, the TAPR Open Hardware License. The OSI president Eric S. Raymond expressed some concerns about certain aspects of the OHL and decided to not review the license.
Around 2010 in context of the Freedom Defined project, the Open Hardware Definition was created as collaborative work of many and is accepted as of 2016 by dozens of organizations and companies.
In July 2011, CERN (European Organization for Nuclear Research) released an open-source hardware license, CERN OHL. Javier Serrano, an engineer at CERN's Beams Department and the founder of the Open Hardware Repository, explained: "By sharing designs openly, CERN expects to improve the quality of designs through peer review and to guarantee their users – including commercial companies – the freedom to study, modify and manufacture them, leading to better hardware and less duplication of efforts". While initially drafted to address CERN-specific concerns, such as tracing the impact of the organization’s research, in its current form it can be used by anyone developing open-source hardware.
Following the 2011 Open Hardware Summit, and after heated debates on licenses and what constitutes open-source hardware, Bruce Perens abandoned the OSHW Definition and the concerted efforts of those involved with it. Openhardware.org, led by Bruce Perens, promotes and identifies practices that meet all the combined requirements of the Open Source Hardware Definition, the Open Source Definition, and the Four Freedoms of the Free Software Foundation Since 2014 openhardware.org is not online and seems to have ceased activity.
The Open Source Hardware Association (OSHWA) at oshwa.org proposes Open source hardware and acts as hub of open source hardware activity of all genres, while cooperating with other entities such as TAPR, CERN, and OSI. The OSHWA was established as an organization in June 2012 in Delaware and filed for tax exemption status in July 2013. After same debates about trademark interferences with the OSI, in 2012 the OSHWA and the OSI signed a co-existence agreement.
Forms of open-source hardware
The term hardware in open source hardware has been historically used in opposition to the term software of open source software. That is, to refer to the electronic hardware on which the software runs (see previous section). However, as more and more non-electronic hardware products are made open source (for example Wikihouse, OpenBeam or Hovalin), this term tends to be used back in its broader sense of "physical product". The field of open source hardware has been shown to go beyond electronic hardware and to cover a larger range of product categories such as machine tools, vehicles and medical equipment. In that sense, hardware refers to any form of tangible product, may it be electronic hardware, mechanical hardware, textile or even construction hardware. The Open Source Hardware (OSHW) Definition 1.0 defines hardware as "tangible artifacts — machines, devices, or other physical things".
Due to a mixture of privacy, security, and environmental concerns, a number of projects have started that aim to deliver a variety of open-source computing devices. Examples include the EOMA68 (SBC in a PCMCIA form-factor, intended to be plugged into a laptop or desktop chassis), Novena (bare motherboard with optional laptop chassis), and GnuBee (series of Network Attached Storage devices).
Several retrocomputing hobby groups have created numerous recreations or adaptations of the early home computers of the 1970s and 80s, some of which include improved functionality and more modern components (such as surface-mount ICs and SD card readers). Some hobbyists have also developed add-on cards (such as drive controllers, memory expansion, and sound cards) to improve the functionality of older computers. Miniaturised recreations of vintage computers have also been created.
One of the most popular types of open-source hardware is electronics. There are numerous companies that provide large varieties of open-source electronics such as Sparkfun, Adafruit and Seeed. In addition, there are NPOs and companies that provide a specific open-source electronic component such as the Arduino electronics prototyping platform. There are numerous examples of speciality open-source electronics such as low-cost voltage and current GMAW open-source 3-D printer monitor and a robotics-assisted mass spectrometry assay platform. Open-source electronics finds various uses, including automation of chemical procedures.
A large range of products including mechanical components have been developed so far, from machine tools to vehicles over musical instruments and medical equipment. Examples of machine-tools are the 3D printers RepRap and Ultimaker as well as the laser cutter Lasersaur. In the category vehicles, we can find bikes like XYZ Space Frame Vehicles and cars like the Tabby OSVehicle. Examples of medical equipment are the echostethoscope echOpen and a wide range of prosthetic hands listed in the review study by Ten Kate et.al. e.g. the OpenBionics’ Prosthetic Hands.
Later, several new licenses have been proposed, designed to address issues specific to hardware designs. In these licenses, many of the fundamental principles expressed in open-source software (OSS) licenses have been "ported" to their counterpart hardware projects. New hardware licenses are often explained as the "hardware equivalent" of a well-known OSS license, such as the GPL, LGPL, or BSD license.
Despite superficial similarities to software licenses, most hardware licenses are fundamentally different: by nature, they typically rely more heavily on patent law than on copyright law, as many hardware designs are not copyrightable. Whereas a copyright license may control the distribution of the source code or design documents, a patent license may control the use and manufacturing of the physical device built from the design documents. This distinction is explicitly mentioned in the preamble of the TAPR Open Hardware License:
... those who benefit from an OHL design may not bring lawsuits claiming that design infringes their patents or other intellectual property.— TAPR Open Hardware License
Noteworthy licenses include:
- The TAPR Open Hardware License: drafted by attorney John Ackermann, reviewed by OSS community leaders Bruce Perens and Eric S. Raymond, and discussed by hundreds of volunteers in an open community discussion
- Balloon Open Hardware License: used by all projects in the Balloon Project
- Although originally a software license, OpenCores encourages the LGPL
- Hardware Design Public License: written by Graham Seaman, admin. of Opencollector.org
- In March 2011 CERN released the CERN Open Hardware License (OHL) intended for use with the Open Hardware Repository and other projects.
- The Solderpad License is a version of the Apache License version 2.0, amended by lawyer Andrew Katz to render it more appropriate for hardware use.
The Open Source Hardware Association recommends seven licenses which follow their open-source hardware definition. From the general copyleft licenses the GNU General Public License (GPL) and Creative Commons Attribution-ShareAlike license, from the HW specific copyleft licenses the CERN Open Hardware License (OHL) and TAPR Open Hardware License (OHL) and from the permissive licenses the FreeBSD license, the MIT license, and the Creative Commons Attribution license. Openhardware.org recommended in 2012 the TAPR Open Hardware License, Creative Commons BY-SA 3.0 and GPL 3.0 license.
Organizations tend to rally around a shared license. For example, OpenCores prefers the LGPL or a Modified BSD License, FreeCores insists on the GPL, Open Hardware Foundation promotes "copyleft or other permissive licenses", the Open Graphics Project uses a variety of licenses, including the MIT license, GPL, and a proprietary license, and the Balloon Project wrote their own license.
The adjective "open-source" not only refers to a specific set of freedoms applying to a product, but also generally presupposes that the product is the object or the result of a "process that relies on the contributions of geographically dispersed developers via the Internet." In practice however, in both fields of open-source hardware and open-source software, products may either be the result of a development process performed by a closed team in a private setting or by a community in a public environment, the first case being more frequent than the second which is more challenging. Establishing a community-based product development process faces several challenges such as: to find appropriate product data management tools, document not only the product but also the development process itself, accepting losing ubiquitous control over the project, ensure continuity in a context of fickle participation of voluntary project members, among others.
One of the major differences between developing open-source software and developing open-source hardware is that hardware results in tangible outputs, which cost money to prototype and manufacture. As a result, the phrase "free as in speech, not as in beer", more formally known as Gratis versus Libre, distinguishes between the idea of zero cost and the freedom to use and modify information. While open-source hardware faces challenges in minimizing cost and reducing financial risks for individual project developers, some community members have proposed models to address these needs Given this, there are initiatives to develop sustainable community funding mechanisms, such as the Open Source Hardware Central Bank.
Extensive discussion has taken place on ways to make open-source hardware as accessible as open-source software. Providing clear and detailed product documentation is an essential factor facilitating product replication and collaboration in hardware development projects. Practical guides have been developed to help practitioners to do so. Another option is to design products so they are easy to replicate, as exemplified in the concept of open-source appropriate technology.
The process of developing open-source hardware in a community-based setting is alternatively called open design, open source development or open source product development. All these terms are instantiations of the open-source model applicable for the development of any product, may it be software, hardware, cultural, educational, and so on. See here for a delineation of these terms.
A major contributor to the production of open-source hardware product designs is the scientific community. There has been considerable work to produce open-source hardware for scientific hardware using a combination of open-source electronics and 3-D printing. Other sources of open-source hardware production are vendors of chips and other electronic components sponsoring contests with the provision that the participants and winners must share their designs. Circuit Cellar magazine organizes some of these contests.
A guide has been published (Open-Source Lab (book) by Joshua Pearce) on using open-source electronics and 3D printing to make open-source labs. Today scientists are creating many such labs, examples include:
- Boston Open Source Science Laboratory, Somerville, Massachusetts
- BYU Open Source Lab, Brigham Young University
- Michigan Tech
- National Tsing Hua University
- OSU Open Source Lab, Oregon State University
- Open Source Research Lab, University of Texas at El Paso
Open hardware companies are experimenting with different business models. In one example, littleBits implements open-source business models by making the design files available for the circuit designs in each littleBits module, in accordance with the CERN Open Hardware License Version 1.2. In another example, Arduino has registered its name as a trademark. Others may manufacture their designs but can't put the Arduino name on them. Thus they can distinguish their products from others by appellation. There are many applicable business models for implementing some open-source hardware even in traditional firms. For example, to accelerate development and technical innovation the photovoltaic industry has experimented with partnerships, franchises, secondary supplier and completely open-source models.
Reception and impact
Richard Stallman, the founder of the free software movement, was in 1999 skeptical on the idea and relevance of Free hardware (his terminology for what is now known as open-source hardware). In a 2015 Wired article he adapted his point of view slightly; while he still sees no ethical parallel between free software and free hardware, he acknowledges the importance. Also, Stallman uses and suggests the term free hardware design over open source hardware, a request which is consistent with his earlier rejection of the term open source software (see also Alternative terms for free software).
Other authors, such as Joshua Pearce have argued there is an ethical imperative for open-source hardware – specifically with respect to open-source appropriate technology for sustainable development. In 2014, he also wrote the book Open-Source Lab: How to Build Your Own Hardware and Reduce Research Costs, which details the development of free and open-source hardware primarily for scientists and university faculty. A new scientific journal has also been introduced by Prof. Pearce in partnership with Elsevier: HardwareX. It has featured numerous examples of applications of open source hardware for scientific purposes.
Find open-source hardware products
Some ongoing initiatives provide indexes of open-source hardware products for different purposes:
- The Open Source Hardware Association provides a certification programme and maintains a directory of certified products.
- The Observatory of Open Source Hardware aims at supporting exchange of best practices between practitioners. It maintains an open access and curated directory of open source hardware products rated according to their degree of openness. This directory contains references of more than 200 complex open source hardware products.
- The P2P Foundation maintains an Open Hardware Directory as well.
- See also some specific lists in Wikipedia:
- Computer numeric control (CNC)
- Fab lab
- Hardware backdoor
- Open innovation
- Open manufacturing
- Open Source Ecology
- Open-source robotics
- Rapid prototyping
- RISC-V—an open-source computer instruction set architecture
- C. Priavolou, "The Emergence of Open Construction Systems: A Sustainable Paradigm in the Construction Sector?", Journal of Futures Studies 23(3), pp. 67-84 (2018).
- Alicia Gibb (Ed.) Building Open Source Hardware: DIY Manufacturing for Hackers and Makers, Addison-Wesley: New York, pp. 253–277 (2015).
- "Free Hardware and Free Hardware Designs". Free Software Foundation Inc.
- Joshua M. Pearce. (2015-06-20). "Return on Investment for Open Source Hardware Development". Science and Public Policy. 43 (2): 192–195. doi:10.1093/scipol/scv034.
- Theo de Raadt (2016-12-03). Open Documentation for Hardware. OpenCON 2006, 2–3 December 2006. Courtyard Venice Airport, Venice/Tessera, Italy.
- Constantine A. Murenin (2006-12-10). "Почему так важно иметь документацию по программированию железа". Linux.org.ru (in Russian).
- Perens, B. 1997. Announcing: The Open Hardware Certification Program. Debian Announce List. .
- The Open Hardware Certification Program on openhardware.org (November 1998).
- Freeman, D. 1998. OHSpec: The Open Hardware Specification Project.
- McNamara, P. 2007a. “Open Hardware”. The Open Source Business Resource (September 2007: Defining Open Source). "Archived copy". Archived from the original on 2012-01-06. Retrieved 2016-03-05.CS1 maint: Archived copy as title (link).
- Ars Technica: TAPR introduces open-source hardware license, OSI skeptical.
- Freedom Defined. 2011. Open Source Hardware Definition. Freedom Defined. .
- CERN launches Open Hardware initiative Archived 2012-07-01 at the Wayback Machine. CERN. 2011.
- Ayass, M. 2011. CERN's Open Hardware License Archived 2011-12-06 at the Wayback Machine.
- Bruce Perens, 2011a. Promoting Open Hardware.
- Bruce Perens. 2011b. Open Hardware – Constitution. Open Hardware.
- You've reached a web site owned by Perens LLC on openhardware.org.
- brief-history-of-open-source-hardware-organizations-and-definitions on OSHWA.org.
- An Important Question on the Open Source Hardware Mark on oshwa.org (August 2012).
- co-existence on oshwa.org (October 2012).
- Replicant – Freedom and privacy/security issues [online]. (2016). Available from http://www.replicant.us/freedom-privacy-security-issues.php. (Accessed 02/22/2016) "The freedom to use the hardware, for any purpose. The freedom to study how the hardware works, and change it so it works as you wish. Access to the hardware design source is a precondition for this. The freedom to redistribute copies of the hardware and its design so you can help your neighbor. The freedom to distribute copies of your modified versions to others. By doing this you can give the whole community a chance to benefit from your changes. Access to the hardware design source is a precondition for this".
- Bonvoisin, Jérémy; Mies, Robert; Boujut, Jean-François; Stark, Rainer (2017-09-05). "What is the 'Source' of Open Source Hardware?". Journal of Open Hardware. 1 (1). doi:10.5334/joh.7. ISSN 2514-1708.
- "Open Source Hardware (OSHW) Definition 1.0". Open Source Hardware Association. 2012-05-26.
- "start [RetroBrew Computers Wiki]". www.retrobrewcomputers.org. Retrieved 2017-11-17.
- "S100 Computers - Cards For Sale". s100computers.com. Retrieved 2017-11-17.
- "Xi 8088 - Malinov Family Web Presence". www.malinov.com. Retrieved 2017-11-17.
- "XTIDE project". Vintage Computer Forum. Retrieved 2017-11-17.
- "Lo-tech Memory Boards - lo-tech.co.uk". www.lo-tech.co.uk. Retrieved 2017-11-17.
- "Lo-tech Audio Boards - lo-tech.co.uk". www.lo-tech.co.uk. Retrieved 2017-11-17.
- "Obsolescence Guaranteed". Obsolescence Guaranteed. Retrieved 2017-11-17.
- A. Pinar, B. Wijnen, G. C. Anzalone, T. C. Havens, P. G. Sanders, J. M. Pearce. Low-cost Open-Source Voltage and Current Monitor for Gas Metal Arc Weld 3-D Printing. Journal of Sensors Vol. 2015, Article ID 876714, 8 pages, 2015. doi:10.1155/2015/876714
- Yuenyong Nilsiam, Amberlee Haselhuhn, Bas Wijnen, Paul Sanders, & Joshua M. Pearce. Integrated Voltage - Current Monitoring and Control of Gas Metal Arc Weld Magnetic Ball-Jointed Open Source 3-D Printer. Machines 3(4), 339–351 (2015). doi:10.3390/machines3040339
- Chiu, S. H. and Urban, P. L., 2015. Robotics-assisted mass spectrometry assay platform enabled by open-source electronics. Biosensors and Bioelectronics, 64, p. 260–268.
- Chen C.-L., Chen T.-R., Chiu S.-H., and Urban P.L., 2017. Dual robotic arm “production line” mass spectrometry assay guided by multiple Arduino-type microcontrollers. Sensors and Actuators B: Chemical 239, p. 608-616.
- Urban P.L. 2015, Universal electronics for miniature and automated chemical assays. Analyst 140, p. 963-975.
- Prabhu G.R.D. and Urban P.L. 2017, The dawn of unmanned analytical laboratories. Trends in Analytical Chemistry 88, p. 41-52.
- Kate, Jelle ten; Smit, Gerwin; Breedveld, Paul (3 April 2017). "3D-printed upper limb prostheses: a review". Disability and Rehabilitation: Assistive Technology. 12 (3): 300–314. doi:10.1080/17483107.2016.1253117. ISSN 1748-3107. PMID 28152642.
- From OpenCollector's "License Zone" Archived 2008-12-05 at the Wayback Machine: GPL used by Free Model Foundry and OpenSPARC; other licenses are used by Free-IP Project, LART (the software is released under the terms of the GNU General Public License (GPL), and the Hardware design is released under the MIT License), GNUBook (defunct).
- Thompson, C. (2011). Build it. Share it. Profit. Can open source hardware work?. Work, 10, 08.
- For a nearly comprehensive list of licenses, see OpenCollector's "license zone" Archived 2008-12-05 at the Wayback Machine
- Hardware_Isn't_Generally_Copyrightable on openhardware.org
- "The TAPR Open Hardware License". Retrieved 16 April 2015.
- transcript of all comments Archived 2008-05-18 at the Wayback Machine, hosted on technocrat.net
- "CERN Open Hardware Licence". Open Hardware Repository. CERN. 2012-07-05. Archived from the original on 2015-09-24. Retrieved 2012-08-15.
- "Open Hardware Repository". Retrieved 16 April 2015.
- "Solderpad licenses". Solderpad.org. Retrieved 2012-08-15.
- Definition on oshwa.org
- FAQ on oshwa.org "What license should I use? In general, there are two broad classes of open-source licenses: copyleft and permissive. Copyleft licenses (also referred to as “share-alike” or “viral”) are those which require derivative works to be released under the same license as the original; common copyleft licenses include the GNU General Public License (GPL) and the Creative Commons Attribution-ShareAlike license. Other copyleft licenses have been specifically designed for hardware; they include the CERN Open Hardware License (OHL) and the TAPR Open Hardware License (OHL). Permissive licenses are those which allow for proprietary (closed) derivatives; they include the FreeBSD license, the MIT license, and the Creative Commons Attribution license. Licenses that prevent commercial use are not compatible with open-source; see this question for more."
- "Recommended Licenses - Open Hardware Wiki".
- Item "What license is used for OpenCores?", from Opencores.org FAQ, retrieved 14 January 2013
- FreeCores Main Page Archived 2008-12-05 at the Wayback Machine, retrieved 25 November 2008
- Open Hardware Foundation, main page, retrieved 25 November 2008
- "The Open Source Hardware Bank | Make". Make: DIY Projects and Ideas for Makers. 2009-03-05. Retrieved 2017-09-09.
- See "Are we going to get the 'source' for what is on the FPGA also?" in the Open Graphics Project FAQ Archived 2008-08-18 at the Wayback Machine, retrieved 25 November 2008
- Balloon License Archived 2008-10-19 at the Wayback Machine, from balloonboard.org
- Gacek, C.; Arief, B. (January 2004). "The many meanings of open source". IEEE Software. 21 (1): 34–40. CiteSeerX 10.1.1.584.5392. doi:10.1109/MS.2004.1259206. ISSN 0740-7459.
- (1), Bonvoisin, Jérémy; (2), Thomas, Laetitia; (1), Mies, Robert; (2), Gros, Céline; (1), Stark, Rainer; (2), Samuel, Karine; (1), Jochem, Roland; (2), Boujut, Jean-François (2017). "Current state of practices in open source product development". DS 87-2 Proceedings of the 21st International Conference on Engineering Design (ICED 17) Vol 2: Design Processes, Design Organisation and Management, Vancouver, Canada, 21-25.08.2017. ISSN 2220-4342.
- Staff, Wired. "Free, as in Beer". WIRED. Retrieved 2017-09-09.
- Benjamin Tincq (2014-11-15). "Business Models for Open Source Hardware".
- 3-D Printing of Open Source Appropriate Technologies for Self-Directed Sustainable Development J. M Pearce, C. Morris Blair, K. J. Laciak, R. Andrews, A. Nosrat and I. Zelenika-Zovko, Journal of Sustainable Development, pp. 17-29 (2010)
- "Best Practices for Open-Source Hardware 1.0". Open Source Hardware Association. 2012-11-21. Retrieved 2017-09-09.
- Halfbakery: Open Source Hardware Initiative
- McAloone, Asta Fjeldsted, Gudrun Adalsteinsdottir, Thomas J. Howard and Tim (2012). "Open Source Development of Tangible Products". DS 71: Proceedings of NordDesign 2012, the 9th NordDesign Conference, Aarlborg University, Denmark. 22-24.08.2012.
- Open Source Product Development - The Meaning and Relevance of | Kerstin Balka | Springer. Forschungs-/Entwicklungs-/Innovations-Management. Gabler Verlag. 2011. ISBN 9783834931535.
- Pearce, Joshua M. 2012. "Building Research Equipment with Free, Open-Source Hardware." Science 337 (6100): 1303–1304.open access
- Joshua M. Pearce,Open-Source Lab:How to Build Your Own Hardware and Reduce Research Costs, Elsevier, 2014. ISBN 9780124104624
- Pearce, Joshua M. (2017-03-21). "Emerging Business Models for Open Source Hardware". Journal of Open Hardware. 1 (1). doi:10.5334/joh.4. ISSN 2514-1708.
- Joshua Pearce. "Pearce Research Group - Current Projects". Retrieved 16 April 2015.
- Pawel Urban. "Urban Lab at NTHU". Retrieved 16 November 2017.
- Pearce, Joshua M. (2017). "Emerging Business Models for Open Source Hardware". Journal of Open Hardware. 1. doi:10.5334/joh.4.
- Saddlemire, Katie (14 April 2015). "What does "Open Source" mean?". littleBits. littleBits. Retrieved 26 May 2015.
- "Build It. Share It. Profit. Can Open Source Hardware Work?". WIRED. 2008-10-20. Retrieved 16 April 2015.
- A. J. Buitenhuis and J. M. Pearce, "Open-Source Development of Solar Photovoltaic Technology", Energy for Sustainable Development, 16, pp. 379-388 (2012). open access
- Byfield, Bruce. "Crowd Supply Boosts Open Hardware » Linux Magazine". Linux Magazine. Retrieved 2017-04-13.
- Stallman, Richard (1999-06-22). "Richard Stallman -- On "Free Hardware"". kernel.org. Retrieved 2016-01-14.
“freedom to copy software is social imperative, but freedom to copy hardware is not so important as hardware is hard to copy”
- Richard Stallman (2015-03-11). "Why We Need Free Digital Hardware Designs". Wired. Wired. Retrieved 2016-01-14.
- Joshua M. Pearce, "The Case for Open Source Appropriate Technology", Environment, Development and Sustainability, 14, p. 425–431 (2012).
- Book of the Day: How to Build Your Own Hardware and Reduce Research Costs, Michel Bauwens, P2P Foundation 12/28/2013
- 3D printing could offer developing world savings on replica lab kit - The Guardian, Friday 21 February 2014 01.59 EST
|Wikimedia Commons has media related to Open hardware.|
- Definition of Open source hardware, freedomdefined.org
- P2P Foundation: Open Hardware Directory
- Writings on Open Source Hardware, Open Collector
- Methods and tools for community based collaboration, OPEN! project
- Open Source Semiconductor Core Licensing, 25 Harvard Journal of Law & Technology 131 (2011)
- Open Source Everywhere, Wired
- Build It. Share It. Profit. Can Open Source Hardware Work?, Wired (2008)
- Richard Stallman: On "Free Hardware", LinuxToday (1999)
- Open Sesame! (Reports), The Economist (2008)
- The Worldwide List of Open Hardware Online Stores (2013)
- The Future with Open-Source Hardware, Digital Qatar (2015)