Hello, The original CryptoZombies is an interactive (free online) code school that teaches you how to write contracts in Solidity through coding your very own crypto-collectible from scratch step-by-step. If anyone is interested - I try to convert the JavaScript-like contracts and samples to (secure) ruby. So far I’ve converted the first three curriculum chapters to runnable (secure) ruby code, see zombies_ch1.rb, zombies_ch2.rb, zombies_ch3.rb. If you have any ideas (questions or comments) on how to convert JavaScript-like Solidity contracts to ruby let us know. Cheers. Prost.