What are the most recommended packages for coding Ruby?


I just found Atom (after being used only with Notepad++ and NetBeans in the past) and I find it so cool in all aspects: from interface to the fact that it has such a strong community and it grows rapidly.
I need Atom mostly for Ruby (which I am still learning) and I would love to hear from someone with more experience especially in Ruby Language, which would be the most recommended and useful package that would be helpful for me.

Thank you very much.