Working in Public: The Making and Maintenance of Open Source Software Highlight

A project’s bus factor is the number of contributors that would need to get hit by a bus before the project is compromised. For example, if a project has a bus factor of 1, that means there is only one maintainer, who, if they were hit by a bus, would take all their knowledge of the project to their grave. The implication is that projects with higher bus factors are more resilient, because knowledge is distributed among more people.