Isn't ruby .RB?
And why have I not seen loads an loads of .py domains for python? Paraguay is a stable enough country for this purpose. Do they limit domain names to residents?
Ruby is .rb, but .ru is affiliated with Ruby via rack (config.ru, where "ru" stands for "rack up")
>Registration restrictions: Second-level registrations prohibited; must have a contact in Paraguay; subdomains have various restrictions; all applications subject to approval by registry
>Structure: Registrations are at third level beneath second-level labels
https://en.wikipedia.org/wiki/.py