Io is like a philosophical exercise in programming: what happens if we strip away the unnecessary and build a language where everything is an object and interaction happens via messages? The result is Io - a language inspired by Smalltalk, Self, Lisp and Lua that offers a unique blend of simplicity and power.

Io has no classes. New objects are created by cloning existing ones, and each object can be modified directly. This makes the language extremely flexible and dynamic. The code is homoiconic - code is data and can be manipulated like any other data structure. That opens up powerful metaprogramming possibilities and makes Io an excellent tool for exploring language design and object-oriented concepts in depth.

Despite its elegant design and intriguing ideas, Io never became widespread. For curious developers it still offers a chance to think differently and explore the fundamentals of programming in a fresh way. If you enjoy experimenting and want to understand how languages can be constructed from simple principles, Io is definitely worth a look.