Picture the maintainer of a small open-source library at the end of a long day. A bug report has arrived from someone she has never met, on another continent. She reads it, assigns the issue to Copilot and closes her laptop. Before she has finished dinner, the work is waiting for her: a branch with the fix, a tidy diff to review and a short note explaining what changed and why. Her name sits on the commits as co-author. She asks for one tweak, the agent makes it, and she opens the pull request, watches the automated tests turn green and merges.
Every step of that small story happens on GitHub. Since 2008 the service has grown from a place to store code into the place where much of the world's software is written, reviewed, tested, secured and shipped. It now counts more than 225 million developers, more than 4 million organizations and more than 800 million repositories, and 90 percent of the Fortune 100 build there.

A repository is more than a folder.#
At GitHub's core is Git, a tool that records every change to a set of files, so nothing is ever truly lost and anyone can see who changed what, and when. A repository holds a project's code along with its entire history. The pull request is the social layer on top: a proposal to merge your changes, with a conversation attached. Reviewers comment on individual lines, automated checks report in, and the change lands only when the project is satisfied.
The scale of that conversation is hard to picture. In the twelve months GitHub measured for its 2025 Octoverse report, developers merged a record 518.7 million pull requests, and on average more than one new developer joined every second. The same report recorded TypeScript overtaking both Python and JavaScript in August 2025 as the language with the most monthly contributors on the platform.
Around the code sit the tools for running a project. Issues track bugs and ideas. Projects turns them into tables, boards and roadmaps. Discussions gives a community a forum of its own, so questions and announcements do not crowd the bug tracker.



