Plruby, Procedures for PostgreSQL in Ruby (github.com)

PL/Ruby is a procedural-language handler that lets you write database functions in Ruby, stored and executed inside PostgreSQL. You get the expressiveness of Ruby and its standard library with the full power of a native PostgreSQL function: plain functions, set-returning functions, triggers, event triggers, and procedures with transaction control.

https://github.com/commandprompt/plruby