The concept of open source software refers to any software where the source code is freely available for anyone to read, edit, and redistribute. This allows programmers to learn how an application works by digging through its source code. Open source projects are typically managed by someone or some organization, with a team of contributors who can contribute code, but not without oversight. Anyone can take the source code of an open source project and use it to start their own project, known as forking. Forks can lead to new applications that become popular, like Libre Office replacing Open Office. Many companies fork open source projects in interesting ways, such as Microsoft Edge using Chromium's open source code. Open source software is generally considered free to download and use, but not necessarily free beer, which refers to the idea of freedom rather than just cost. The concept of open source uses copyright law to enforce sharing through copyleft licenses.