Use single-quoted strings in Ruby implementation.
Declare encoding of the Ruby implementation as UTF-8.
Add note about global variables in help text.
More idiomatic Ruby code with rubocop.
Some more idiomatic Ruby code.
Fix search path in Bash front end.

The directory of the script is the one that should be added to search path, not the current directory.
Use subfolders for each implementation.
Small refactoring in Ruby code.
Add changelog.