Open source software is software with source code that anyone can inspect, modify, and enhance.
“Source code” is the part of software that most computer users don’t ever see; it’s the code computer programmers can manipulate to change how a piece of software—a “program” or “application”—works. Programmers who have access to a computer program’s source code can improve that program by adding features to it or fixing parts that don’t always work correctly.
How to View the Source Code
Once you’ve found the GitHub repository that hosts the software’s source code, you’ll find that everything is organized in a basic directory tree. For files, GitHub makes viewing code very easy.
As a development platform, GitHub neatly formats source code through its web interface. Almost all reputable projects will include a README.md, which is a markdown file that displays helpful information about the repository and its structure. When you navigate to a repository, scroll down and you’ll see the contents of this file.
The repository’s README.md is important to check out because it often points users in the direction of the source code that they may be interested in. A repository can be filled with all sorts of code and other data, some of it completely useless to you, so this file is your roadmap.
Once you figure out where in the repository the code that you’re interested in is located, all you have to do is click through the repository’s directory tree to get where you want to go.
Clicking on a file will display it with the proper syntax highlighting.
For quick inspecting, GitHub’s web interface is great. However, for more complicated source code, you may want to view multiple files at the same time or over a long period of time. In this case, we recommend downloading and viewing the source code through a text editor, such as Sublime Text.
Downloading The Source Code
Downloading a repository from GitHub takes just two clicks.
At the top of each repository, beneath the row displaying the total number of commits, branches, packages, releases, and contributors, you’ll see a green button labeled Clone or download. Click on it and select Download ZIP.
By default, this will begin downloading the current repository’s master branch as a ZIP file. When complete, all you need to do is extract the archive to a local folder on your computer. Then, using a text editor, you can open any of the repository’s files in a much quicker way that doesn’t require a browser.
If you aren’t an experienced coder, GitHub can be a little confusing at first. If you just think of it as an open directory of source code, with a readme at the top level, it’s not too intimidating. Viewing source code using GitHub is simple, both locally and through its web interface.