There are some really great guides for starting a new open source projects, yet when it comes to dealing with a possibly abandoned, unmaintained project, there is no definitive guide for users, contributors, or maintainers.
I hope that this can be a useful guide for our community.
When do you declare that an open source project has been abandoned? How many
days have to go by until you start maintaining your own fork? What's the
standard for communicating with maintainers, contributors, and users? How do
n competing OSS forks of popular projects? How do you avoid
duplicated work by people who want to maintain popular, but unmaintained OSS
projects? What's the best way to find that one fork everybody is using?