Digo is a Ruby gem that translates short sentences between several languages. It defines a number of methods in the String class and returns an array of possible translations. Use it in Ruby:

irb> require 'digo'
=> true
irb> 'pájaro'.es_to_en
=> ["bird", "aves", "avian", "birds", "avians", "songster", "class aves", "domestic bird", "birds domestic"]

It ships with a convenient REPL:

$ digo
Digo REPL
digo> help
Usage:
  <text> <from> <to>
Examples:
  digo> amigo sp en      # => array of translations from spanish to english
  digo> hi there en fr   # => array of translations from english to french

Available languages and codes:
  chinese => zh
  english => en
  french => fr
  german => de
  italian => it
  japanese => jp
  korean => ko
  portuguese => pt
  spanish => es

digo> amigo es ko
친구
우정
ì¹êµ¬
가까운 친구도 없나이다

Long translations are less accurate, but for short phrases or single words Digo can be surprisingly useful.