Is there an offline IDE for ruby on rails ?

Question

Ruby on rails offline IDE

Answer 1

On which OS?
Probably the most used is JB's RubyMine.
You can also use text editor (Vim, Atom...) and run the code in terminal (on Linux/UNIX/WSL just install 'ruby').
Make yourself a directory with .rb files with code. In terminal just enter that directory and run the code (let's say you have your code in a file called "demo.rb", so you just have to write 'ruby demo.rb' in the terminal).
You can also use interactive Ruby console by entering 'irb' in the terminal.