The gem zeus
does exactly this.
The command rails server
often takes too long to start up a simple WEBrick server. And in case something major changes in your application, you often have to restart the server.
After installing the gem zeus, we can do all of this in under a second. And we don't have to restart the server.
gem install zeus
zeus start
zeus server
This is one of the few gems that I have used that make Ruby on Rails even more fun and faster to use!