Bus factor of top GitHub projects

The concept of the "bus factor" measures how many key contributors need to be lost before a project is jeopardized, and was analyzed for the top 1,000 GitHub repositories by star count using the GitHub API and the truckfactor library. The study found that nearly half of the projects have a bus factor of two or less, indicating a high vulnerability to losing key developers, while only 10% of projects have a bus factor of six or higher. Contrary to expectations, there was no correlation between the number of stars a repository has and its bus factor. Projects using web-based languages like JavaScript, HTML, CSS, and TypeScript tend to have lower bus factors compared to those using general-purpose languages such as Python, C, and Java. Notably, machine learning projects were more likely to have higher bus factors. Among the most-starred repositories, JavaScript was the most popular language tag, and labels like Hacktoberfest were also prevalent, reflecting their role in encouraging open-source contributions.