YAJSW In case of YAJSW I found this answer with better understanding. It's of course pretty similar to link you gave, anyway keep in mind that it's more often advised to use dist command instead of stage as it has got better developers attention (more bugs fixed in dist). And Mikhail's answer is just clearer (vote him up!) RUNNING_PID In case of RUNNING_PID, there was some pull requests which sugg