Open-source software in the context of Vim (text editor)

Safari is a web browser developed by Apple. It is built into several of Apple's operating systems, including macOS, iOS, iPadOS, and visionOS, and uses Apple's open-source browser engine WebKit, which was derived from KHTML.

Safari was introduced in an update to Mac OS X Jaguar in January 2003, and made the default web browser with the release of Mac OS X Panther that same year. It has been included with the iPhone since the first-generation iPhone in 2007. At that time, Safari was the fastest browser on the Mac. Between 2007 and 2012, Apple maintained a Windows version, but abandoned it due to low market share. In 2010, Safari 5 introduced a reader mode, extensions, and developer tools. Safari 11, released in 2017, added Intelligent Tracking Prevention, which uses artificial intelligence to block web tracking. Safari 13 added support for Apple Pay, and authentication with FIDO2 security keys. Its user interface was redesigned in Safari 15, Safari 18, and Safari 26.

Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentralized software development model that encourages open collaboration.A main principle of open source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open source eCommerce, open source appropriate technology, and open source drug discovery.

Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase open source became widely adopted, developers and producers used a variety of other terms, such as free software, shareware, and public domain software. Open source gained hold with the rise of the Internet. The open-source software movement arose to clarify copyright, licensing, domain, and consumer issues.

Android is an operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen-based mobile devices such as smartphones and tablet computers. Android has historically been developed by a consortium of developers known as the Open Handset Alliance, but its most widely used version is primarily developed by Google. First released in 2008, Android is the world's most widely used operating system; it is the most used operating system for smartphones, and also most used for tablets; the latest version, released on June 10, 2025, is Android 16.

At its core, the operating system is known as the Android Open Source Project (AOSP) and is free and open-source software (FOSS) primarily licensed under the Apache License. However, most devices run the proprietary Android version developed by Google, which ships with additional proprietary closed-source software pre-installed, most notably Google Mobile Services (GMS), which includes core apps such as Google Chrome, the digital distribution platform Google Play, and the associated Google Play Services development platform. Firebase Cloud Messaging is used for push notifications. While AOSP is free, the "Android" name and logo are trademarks of Google, who restrict the use of Android branding on "uncertified" products. The majority of smartphones based on AOSP run Google's ecosystem—which is known simply as Android—some with vendor-customized user interfaces and software suites, for example One UI. Numerous modified distributions exist, which include competing Amazon Fire OS, community-developed LineageOS; the source code has also been used to develop a variety of Android distributions on a range of other devices, such as Android TV for televisions, Wear OS for wearables, and Meta Horizon OS for VR headsets.

Wiki software (also known as a wiki engine or a wiki application) is collaborative software that runs a wiki, which allows the users to create and collaboratively edit pages or entries via a web browser. A wiki system is usually a web application that runs on one or more web servers. The content, including previous revisions, is usually stored in either a file system or a database. Wikis are a type of web content management system, and the most commonly supported off-the-shelf software that web hosting facilities offer.

There are dozens of actively maintained wiki engines. They vary in the platforms they run on, the programming language they were developed in, whether they are open-source or proprietary, their support for natural language characters and conventions, and their assumptions about technical versus social control of editing.

Free and open-source software (FOSS) is software available under a license that gives users the right to use, share, modify, and distribute the software – modified or not – to everyone and provides the means to exercise those rights using the software's source code. FOSS is an inclusive umbrella term encompassing free software and open-source software. The rights guaranteed by FOSS originate from the "Four Essential Freedoms" of The Free Software Definition and the criteria of The Open Source Definition. All FOSS can have publicly available source code, but not all source-available software is FOSS. FOSS is the opposite of proprietary software, which is licensed restrictively or has undisclosed source code.

The historical precursor to FOSS was the hobbyist and academic public domain software ecosystem of the 1960s to 1980s. Free and open-source operating systems such as Linux distributions and descendants of BSD are widely used, powering millions of servers, desktops, smartphones, and other devices. Free-software licenses and open-source licenses have been adopted by many software packages. Reasons for using FOSS include decreased software costs, increased security against malware, stability, privacy, opportunities for educational usage, and giving users more control over their own hardware.

An open file format is a file format for storing digital data, defined by an openly published specification usually maintained by a standards organization, and which can be used and implemented by anyone. An open file format is licensed with an open license.For example, an open format can be implemented by both proprietary and free and open-source software, using the typical software licenses used by each. In contrast to open file formats, closed file formats are considered trade secrets.

Depending on the definition, the specification of an open format may require a fee to access or, very rarely, contain other restrictions. The range of meanings is similar to that of the term open standard.

Source-available software is software released through a source code distribution model that includes arrangements where the source can be viewed, and in some cases modified, but without necessarily meeting the criteria to be called open-source. The licenses associated with the offerings range from allowing code to be viewed for reference to allowing code to be modified and redistributed for both commercial and non-commercial purposes.

Node.js is a cross-platform, open-source JavaScript runtime environment that can run on Windows, Linux, Unix, macOS, and more. Node.js runs on the V8 JavaScript engine, and executes JavaScript code outside a web browser. According to the Stack Overflow Developer Survey, Node.js is one of the most commonly used web technologies.

Node.js lets developers use JavaScript to write command line tools and server-side scripting. The ability to run JavaScript code on the server is often used to generate dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm, unifying web-application development around a single programming language, as opposed to using different languages for the server- versus client-side programming.

FUDforum is a free and open-source Internet forum software, originally produced by Advanced Internet Designs Inc., that is now maintained by the user community. The name "FUDforum" is an abbreviation of Fast Uncompromising Discussion forum. It is comparable to other forum software. FUDforum is customizable and has a large feature set relative to other forum packages.

FUDforum runs on a number of operating systems that are able to support the PHP programming language, including Unix, Linux and Windows systems. The interface is based on HTML5 with CSS, jQuery and AJAX.

NASA WorldWind is an open-source (released under the NOSA license and the Apache 2.0 license) virtual globe. According to the website, "WorldWind is an open source virtual globe API. WorldWind allows developers to quickly and easily create interactive visualizations of 3D globe, map and geographical information. Organizations around the world use WorldWind to monitor weather patterns, visualize cities and terrain, track vehicle movement, analyze geospatial data and educate humanity about the Earth." It was first developed by NASA in 2003 for use on personal computers and then further developed in concert with the open source community since 2004. As of 2017, a web-based version of WorldWind is available online. An Android version is also available.

The original version relied on .NET Framework, which ran only on Microsoft Windows. The more recent Java version, WorldWind Java, is cross platform, a software development kit (SDK) aimed at developers and, unlike the old .NET version, not a standalone virtual globe application in the style of Google Earth. The WorldWind Java version was awarded NASA Software of the Year in November 2009. The program overlays NASA and USGS satellite imagery, aerial photography, topographic maps, Keyhole Markup Language (KML) and Collada files.

Bitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown entity published a white paper under the pseudonym of Satoshi Nakamoto. Use of bitcoin as a currency began in 2009, with the release of its open-source implementation. From 2021 to 2025, El Salvador adopted it as legal tender currency before revoking it. As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries.

Bitcoin works through the collaboration of computers, each of which acts as a node in the peer-to-peer bitcoin network. Each node maintains an independent copy of a public distributed ledger of transactions, called a blockchain, without central oversight. Transactions are validated through the use of cryptography, preventing one person from spending another person's bitcoin, as long as the owner of the bitcoin keeps certain sensitive data secret.

The Mozilla Foundation is an American non-profit organization that exists to support and collectively lead the open source Mozilla project. Founded in July 2003, the organization sets the policies that govern development, operates critical infrastructure, and controls Mozilla trademarks and copyrights. It owns two taxable subsidiaries: the Mozilla Corporation, which employs many Mozilla developers and coordinates releases of the Mozilla Firefox web browser, and MZLA Technologies Corporation, which employs developers to work on the Mozilla Thunderbird email client and coordinate its releases. The Mozilla Foundation was founded by the Netscape-affiliated Mozilla Organization. The organization is currently based in the Silicon Valley city of Mountain View, California, United States.

The Mozilla Foundation describes itself as "a non-profit organization that promotes openness, innovation and participation on the Internet". The Mozilla Foundation is guided by the Mozilla Manifesto, which lists 10 principles which Mozilla believes "are critical for the Internet to continue to benefit the public good as well as commercial aspects of life".

Amazon Silk is a web browser developed by Amazon. It was launched in November 2011 for Amazon Fire and Fire Phone, and a Fire TV version was launched in November 2017. The addition of Silk to the Echo Show was announced at an Amazon event in September 2018.

The browser uses a split architecture where some of the processing is performed on Amazon's servers to improve webpage loading performance. It is based on the open source Chromium project that uses the Blink and V8 engines.

ArduPilot is an autopilot software program that can control multirotor drones, fixed-wing and VTOL aircraft, RC helicopters, ROVs, ground rovers, boats, submarines, uncrewed surface vessels (USVs), AntennaTrackers and blimps. It is published as open source software under the GNU GPL version 3.

ArduPilot was originally developed by hobbyists to control model aircraft and rovers and has evolved into a full-featured and reliable autopilot used by industry, research organisations, amateurs, and militaries. In June 2025 ArduPilot was used successfully by the Ukrainian armed forces during the Russo-Ukrainian War to make aerial drone attacks on Russian air bases.

Deprecation is the discouragement of use of something human-made, such as a linguistic term, a proper name, a feature, design, functionality, piece of code, or practice. Typically a thing previously used is deprecated because it is—or is claimed or thought to be—inferior compared to other options now available. Deprecation is thus a mechanism for future improvement. Deprecation implies that the community (generally, or a community of experts, or a professional body governing a sector or industry) has determined that future use—of the term, name, device, design, or feature—is unwise; but also that its replacement or removal, from that which is extant, is not required or is non-urgent.

Something may be deprecated even though past or extant applications of it might still be useful or functional in particular contexts—the goal here need not be the complete replacement of that which has been deprecated but rather an improvement on some broad metric (eg, safety) of the stock of that thing over time. Thus: deprecation of archaic terms to obtain consistency and readability in language/terminology; deprecation of obsolete electrical components to improve safety and compatibility in the housing stock; or deprecation of certain shared code to improve an open-source software project.

LineageOS is an open source Android operating system for smartphones, tablets, and set-top boxes. It is community-developed and serves as the successor to CyanogenMod, from which it was forked in December 2016. As of 2025, there are about 4.5 million devices running LineageOS.