thin binary package in Ubuntu Xenial s390x

 Thin is a Ruby web server that glues together 3 of the best Ruby
 libraries in web history:
   * the Mongrel parser, the root of Mongrel's speed and security
   * Event Machine, a network I/O library with extremely high
     scalability, performance and stability
   * Rack, a minimal interface between webservers and Ruby frameworks
 .
 Which makes it, with all humility, the most secure, stable, fast and
 extensible Ruby web server bundled in an easy to use package for your own
 pleasure.

Source package