Dylan is an object-functional language originally created by Apple for the Newton. Dylan is a direct descendant of Scheme and CLOS (without the Lisp syntax) with a programming model designed to support efficient machine code generation, including fine-grained control over dynamic and static behaviors.
If you want to play around without having to install anything, try out the Playground. It has a fixed set of imports so you don’t have to worry about how to define libraries and modules right away.
Then move on to one of these in-depth guides:
An Introduction to Dylan provides a high-level overview of language features.
Dylan Programming Guide is a book length Dylan tutorial.
Or explore all the docs, including cheat sheets, articles, and all the library docs.