computer science

GitHub

GitHub is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand GitHub rather than just read about it. In short: 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.

Key takeaways

GitHub belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect GitHub to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GitHub from memory before moving on to harder problems.

Reference excerpt

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, headquartered in San Francisco, is operated by Github, Inc., a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. As of January 2023, 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 June 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 (open allocation), 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 (~$322 million in 2024) of venture capital in a series B round. The lead investor was Sequoia Capital, and other investors were Andreessen Horowitz, Thrive Capital, IVP (Institutional Venture Partners), and other venture capital funds. The company was then valued at approximately $2 billion. As of 2023, 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 (DDoS) 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 (COO) 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 its intention to find a direct replacement.

Acquisition by Microsoft

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with GitHub

Start with the simplest possible case. Write down what GitHub claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to GitHub before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about GitHub ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of GitHub

In research: GitHub appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses GitHub in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: GitHub is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2018 mergers and acquisitions, Bug and issue tracking software, Cloud computing providers, so understanding it makes those chapters shorter.
In everyday life: Look for GitHub outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study GitHub in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GitHub means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain GitHub out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GitHub in simple terms?

Why does GitHub matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study GitHub?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on GitHub.