Getting started with CloudLinux OS Shared
Ruby Selector allows you to deploy Ruby applications on cPanel/WHM servers running EasyApache or LiteSpeed.
You can install Ruby Selector according to this documentation article. The list of supported Ruby versions is available in the article as well.
You need to uncheck Hide Ruby App in web-interface first in LVE Manager -> Options -> User Interface Settings in order to make it available to your customers.
Ruby resources can be limited by LVE similar to how it is done for PHP scripts.
You can find more information on how to manage end-user Ruby applications in online documentation.