GitHub
GitHub is a proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. GitHub is operated by Github, Inc., a subsidiary of Microsoft since 2018 which is headquartered in San Francisco.
It is commonly used to host open source software development projects. GitHub reported having over 100 million developers and more than 420 million repositories, including at least 28 million public repositories. It is the world's largest source code host as of 2023 Over five billion developer contributions were made to more than 500 million open source projects in 2024.
About
Founding
The development of the GitHub platform began on October 19, 2007. The site was launched in April 2008 by Tom Preston-Werner, Chris Wanstrath, P. J. Hyett and Scott Chacon after it had been available for a few months as a beta release.Structure of the organization
GitHub was originally a flat organization with no middle managers, instead relying on self-management. Employees could choose to work on projects that interested them, but the chief executive set salaries.In 2014, the company added a layer of middle management in response to harassment allegations against its co-founder and then-CEO, Thomas Preston-Werner, and his wife Theresa. As a result of the scandal, Preston-Werner resigned from his position as CEO. Co-founder and Product lead, Chris Wanstrath, became CEO. Julio Avalos, then General Counsel and Administrative Officer, assumed control over GitHub's business operations and day-to-day management.
Finance
GitHub was a bootstrapped start-up business, which in its first years provided enough revenue to be funded solely by its three founders and start taking on employees.In July 2012, four years after the company was founded, Andreessen Horowitz invested $100 million in venture capital with a $750 million valuation.
In July 2015 GitHub raised another $250 million of venture capital in a series B round. The lead investor was Sequoia Capital, and other investors were Andreessen Horowitz, Thrive Capital, IVP and other venture capital funds. The company was then valued at approximately $2 billion.
GitHub was estimated to generate $1 billion in revenue annually.
History
The GitHub service was developed by Chris Wanstrath, P. J. Hyett, Tom Preston-Werner, and Scott Chacon using Ruby on Rails, and started in February 2008. The company, GitHub, Inc., was formed in 2007 and is located in San Francisco.On February 24, 2009, GitHub announced that within the first year of being online, GitHub had accumulated over 46,000 public repositories, 17,000 of which were formed in the previous month. At that time, about 6,200 repositories had been forked at least once, and 4,600 had been merged.
That same year, the site was used by over 100,000 users, according to GitHub, and had grown to host 90,000 unique public repositories, 12,000 having been forked at least once, for a total of 135,000 repositories.
In 2010, GitHub was hosting 1 million repositories. A year later, this number doubled. ReadWriteWeb reported that GitHub had surpassed SourceForge and Google Code in total number of commits for the period of January to May 2011. On January 16, 2013, GitHub passed the 3 million users mark and was then hosting more than 5 million repositories. By the end of the year, the number of repositories was twice as great, reaching 10 million repositories.
In 2015, GitHub opened an office in Japan, its first outside of the U.S.
On February 28, 2018, GitHub fell victim to the third-largest distributed denial-of-service attack in history, with incoming traffic reaching a peak of about 1.35 terabits per second.
On June 19, 2018, GitHub expanded its GitHub Education by offering free education bundles to all schools.
On June 11, 2019, it was announced that former Bitnami chief operating officer and co-founder, Erica Brescia, would be GitHub's COO.
On November 3, 2021, GitHub announced that CEO Nat Friedman, who became CEO when Microsoft acquired GitHub, was stepping down as CEO and GitHub's chief product officer, Thomas Dohmke, would become CEO on November 15.
In June 2025, the amount of repositories on GitHub surpassed one billion. Notably, the billionth repository contained nothing but the word "shit".
On August 11, 2025 Thomas Dohmke announced that he was to step down as CEO at the end of 2025, to pursue entrepreneurial endeavors. Microsoft did not immediately share their intention to find a direct replacement.
Acquisition by Microsoft
From 2012, Microsoft became a significant user of GitHub, using it to host open-source projects and development tools such as.NET Core, Chakra Core, MSBuild, PowerShell, PowerToys, Visual Studio Code, Windows Calculator, Windows Terminal and the bulk of its product documentation.On June 4, 2018, Microsoft announced its intent to acquire GitHub for US$7.5 billion. The deal closed on October 26, 2018. GitHub continued to operate independently as a community, platform and business. Under Microsoft, the service was led by Xamarin's Nat Friedman, reporting to Scott Guthrie, executive vice president of Microsoft Cloud and AI.
There have been concerns from developers Kyle Simpson, JavaScript trainer and author, and Rafael Laguna, CEO at Open-Xchange over Microsoft's purchase, citing uneasiness over Microsoft's handling of previous acquisitions, such as Nokia's mobile business and Skype.
This acquisition was in line with Microsoft's business strategy under CEO Satya Nadella, which has seen a larger focus on cloud computing services, alongside the development of and contributions to open-source software. Harvard Business Review argued that Microsoft was intending to acquire GitHub to get access to its user base, so it can be used as a loss leader to encourage the use of its other development products and services.
Concerns over the sale bolstered interest in competitors: Bitbucket, SourceForge and GitLab reported that they had seen spikes in new users intending to migrate projects from GitHub to their respective services.
In September 2019, GitHub acquired Semmle, a code analysis tool. In February 2020, GitHub launched in India under the name GitHub India Private Limited. In March 2020, GitHub announced that it was acquiring npm, a JavaScript packaging vendor, for an undisclosed sum of money. The deal was closed on April 15, 2020.
In early July 2020, the GitHub Archive Program was established to archive its open-source code in perpetuity.
Mascot
GitHub's mascot is Mona, an anthropomorphized "octocat" with five octopus-like arms. The character was created by graphic designer Simon Oxley as clip art to sell on iStock, a website that enables designers to market royalty-free digital images. The illustration GitHub chose was a character that Oxley had named Octopuss. Since GitHub wanted Octopuss for their logo, they negotiated with Oxley to buy exclusive rights to the image.GitHub renamed Octopuss to Octocat, and trademarked the character along with the new name. Later, GitHub hired illustrator Cameron McEfee to adapt Octocat for different purposes on the website and promotional materials; McEfee and various GitHub users have since created hundreds of variations of the character, which are available on .
Services
Projects on GitHub can be accessed and managed using the standard Git command-line interface; all standard Git commands work with it. GitHub also allows users to browse public repositories on the site. Multiple desktop clients and Git plugins are also available. In addition, the site provides social networking-like functions such as feeds, followers, wikis, and a social network graph to display how developers work on their versions of a repository and what fork is newest.Anyone can browse and download public repositories, but only registered users can contribute content to repositories. With a registered user account, users can have discussions, manage repositories, submit contributions to others' repositories, and review changes to code. GitHub began offering limited private repositories at no cost in January 2019. Previously, only public repositories were free. On April 14, 2020, GitHub made "all of the core GitHub features" free for everyone, including "private repositories with unlimited collaborators."
The fundamental software that underpins GitHub is Git itself, written by Linus Torvalds, creator of Linux. The additional software that provides the GitHub user interface was written using Ruby on Rails and Erlang by GitHub, Inc. developers Wanstrath, Hyett, and Preston-Werner.
Scope
The primary purpose of GitHub is to facilitate the version control and issue tracking aspects of software development. Labels, milestones, responsibility assignment, and a search engine are available for issue tracking. For version control, Git allows pull requests to propose changes to the source code. Users who can review the proposed changes can see a diff between the requested changes and approve them. In Git terminology, this action is called "committing" and one instance of it is a "commit." A history of all commits is kept and can be viewed at a later time.In addition, GitHub supports the following formats and features:
- Documentation, including automatically rendered README files in a variety of Markdown-like file formats
- Wikis, with some repositories consisting solely of wiki content. These include curated lists of recommended software which have become known as awesome lists.
- GitHub Codespaces, an online IDE providing users with a virtual machine intended to be a work environment to build and test code
- Graphs: pulse, contributors, commits, code frequency, punch card, network, members
- Integrations Directory
- Email notifications
- Discussions
- Option to subscribe someone to notifications by @ mentioning them.
- Emojis
- Nested task-lists within files
- Visualization of geospatial data
- 3D render files can be previewed using an integrated STL file viewer that displays the files on a "3D canvas." The viewer is powered by WebGL and Three.js.
- Support for previewing many common image formats, including Photoshop's PSD files
- PDF document viewer
- Security Alerts of known Common Vulnerabilities and Exposures in different packages