Open-source hardware consists of physical artifacts of technology designed and offered by the open design movement. Both free and open-source software (FOSS) as well as open-source hardware is created by this open-source culture movement and applies a like concept to a variety of components. The term usually means that information about the hardware is easily discerned. 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 with the FOSS approach.
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, or IP cores.
Additionally, several new licenses have been proposed. These licenses are 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. 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. 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. 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.
Extensive discussion has taken place on ways to make open-source hardware as accessible as open-source software. Discussions focus on multiple areas, such as the level at which open-source hardware is defined, ways to collaborate in hardware development, as well as a model for sustainable development by making open-source appropriate technology. In addition there has been considerable work to produce open-source hardware for scientific hardware using a combination of open-source electronics and 3-D printing.
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, as well as tools like KiCad to make schematic development more accessible to more users.
Often vendors of chips and other electronic components will sponsor contests with the provison that the participants and winners must share their designs. Circuit Cellar magazine organizes some of these contests.
- Boston Open Source Science Laboratory, Somerville, Massachusetts
- BYU Open Source Lab, Brigham Young University
- Michigan Tech
- OSU Open Source Lab, Oregon State University
- Open Source Research Lab, University of Texas at El Paso
- Stanford Open Source Lab, Stanford University
Open hardware companies are experimenting with different business models. Arduino, for example, has registered their name as a trademark. Others may manufacture their designs, but they 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.
- List of open-source hardware projects
- 3D printing
- Computer-aided design
- Open Design Alliance
- Open innovation
- Open-source computing hardware
- Open Source Initiative
- Open Source Lab (book)
- Rapid prototyping
- From OpenCollector's "License Zone": GPL used by Free Model Foundry and ESA Sparc; other licenses used by Free-IP Project, LART (defunct), GNUBook (defunct).
- For a nearly comprehensive list of licenses, see OpenCollector's "license zone"
- Item "What license is used for OpenCores?", from Opencores.org FAQ, retrieved 14 January 2013
- FreeCores Main Page, retrieved 25 November 2008
- Open Hardware Foundation, main page, retrieved 25 November 2008
- See "Are we going to get the 'source' for what is on the FPGA also?" in the Open Graphics Project FAQ, retrieved 25 November 2008
- Balloon License, from balloonboard.org
- TAPR Open Hardware License
- transcript of all comments, hosted on technocrat.net
- "CERN Open Hardware Licence". Open Hardware Repository. CERN. 2012-07-05. Retrieved 2012-08-15.
- Open Hardware Repository
- "licenses". Solderpad.org. Retrieved 2012-08-15.
- , Writings on Open Source Hardware
-  MAKE: Blog: Open source hardware, what is it? Here's a start...
- , Halfbakery: Open Source Hardware Initiative
- J. M Pearce, C. Morris Blair, K. J. Laciak, R. Andrews, A. Nosrat and I. Zelenika-Zovko, "3-D Printing of Open Source Appropriate Technologies for Self-Directed Sustainable Development", Journal of Sustainable Development 3(4), pp. 17-29 (2010)
- 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
- "Free, as in Beer", by Lawrence Lessig, Wired
- , Business Models for Open Source Hardware Design
- Open Source Hardware Central Bank, from "Make: Online : The Open Source Hardware Bank, retrieved 26 April 2010
- Michigan Tech Lab
- Clive Thompson, "Build It. Share It. Profit. Can Open Source Hardware Work?", Wired Magazine, October 2008
- 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
|Wikimedia Commons has media related to Open hardware.|
- Open-source hardware in DMOZ
- Open Circuits wiki
- Open Source Semiconductor Core Licensing, 25 Harvard Journal of Law & Technology 131 (2011)
- Definition of Open source hardware, freedomdefined.org
- P2P Foundation: Open Hardware Directory
- Writings on Open Source Hardware, Open Collector
- Open Source Everywhere, Wired
- Build It. Share It. Profit. Can Open Source Hardware Work?, Wired
- Richard Stallman: On "Free Hardware", LinuxToday
- Open Sesame! (Reports), The Economist
- The Worlwide List of Open Hardware Online Stores
- Discover your hardware (FSF)