Steve Dekorte invented the Io language in 2002. It’s always written with an uppercase I followed by a lowercase o. Io is a prototype language like Lua or JavaScript, meaning every object is a clone of another.
Written as an exercise to help Steve understand how interpreters work, Io started as a hobbyist language and remains pretty small today. You can learn the syntax in about fifteen minutes and the basic mechanics of the language in thirty. There are no surprises. But the libraries will take you a little longer. The complexity and the richness comes from the library design.
Today, most of Io’s community is focused on Io as an embeddable language with a tiny virtual machine and rich concurrency. The core strengths are richly customizable syntax and function, as well as a strong concurrency model. Try to focus on the simplicity of the syntax and the prototype programming model. I found that after Io, I had a much stronger understanding of how JavaScript worked.