A webapp for calculating the score for a Github repository: http://reposcore.appspot.com/
The strength of a Github repository can be calculated from several different factors, including how recently the repository has been updated, how many people contribute to the repository, and how many issues and forks have been created. Repo Score uses the GitHub API to measure how well a repository scores in each scoring criteria, and allows you to determine at a glance how well maintained a repository is, due to the score color coding.