Description:

This is an automatic reloading version of the rackup command that's shipped
with Rack. It can be used as an alternative to the complex reloading logic
provided by web frameworks or in environments that don't support
application reloading.

The shotgun command starts one of Rack's supported servers (e.g., mongrel,
thin, webrick) and listens for requests but does not load any part of the
actual application. Each time a request is received, it forks, loads the
application in the child process, processes the request, and exits the
child process. The result is clean, application-wide reloading of all
source files and templates on each request.