# Io

> A small, prototype-based programming language — now targeting WASM/WASI.

## Documentation

- [Documentation](/docs/): Guides, tutorial, language reference, and design notes.
- [Book](/docs/Book/): The original Io book, organized by chapter.
- [Appendix](/docs/Book/Appendix/): Grammar reference and citations.
- [Concurrency](/docs/Book/Concurrency/): Coroutines, actors, futures, and Io's concurrency model.
- [Control Flow](/docs/Book/Control%20Flow/): Branching, loops, exceptions, and scope.
- [Introduction](/docs/Book/Introduction/): The origins, philosophy, and influences behind Io.
- [Objects](/docs/Book/Objects/): Slots, prototypes, cloning, and differential inheritance.
- [Primitives](/docs/Book/Primitives/): Built-in objects: numbers, strings, lists, maps, files, and more.
- [Syntax](/docs/Book/Syntax/): Io's minimal grammar: expressions, messages, and operators.
- [Guide](/docs/Guide/): Comprehensive language guide: syntax, messages, objects, control flow, concurrency, and more.
- [Reference](/docs/Reference/): Browse every built-in object and method in Io's standard library.
- [Style Guide](/docs/Style%20Guide/): How to write idiomatic Io — naming, formatting, comments, and the patterns used throughout the standard library.
- [Technical Notes](/docs/Technical%20Notes/): Implementation notes and design docs on WASM targeting, stackless evaluation, and future work.
- [Future Work](/docs/Technical%20Notes/Future%20Work/): Design notes and proposals for upcoming changes.
- [Exceptions](/docs/Technical%20Notes/Future%20Work/Exceptions/): Design notes on the current exception system and proposed improvements.
- [Stackless](/docs/Technical%20Notes/Stackless/): Io's iterative evaluator, continuations, and coroutines.
- [Stackless VM Examples](/docs/Technical%20Notes/Stackless/Examples/): Patterns enabled by the heap-allocated frame-based evaluator: portable coroutines, TCO, frame introspection, and robust exception handling.
- [Stackless Evaluator Report](/docs/Technical%20Notes/Stackless/Report/): Design and status notes on the heap-allocated frame-based evaluator.
- [WASM](/docs/Technical%20Notes/WASM/): Running Io in the browser via WebAssembly.
- [Browser Target](/docs/Technical%20Notes/WASM/Browser%20Target/): Io runs in the browser as a WebAssembly module. The browser build compiles the full VM into a WASM reactor module that JS loads and drives via exported functions.
- [DOM Interop](/docs/Technical%20Notes/WASM/DOM%20Interop/): Io code running in the browser can query, create, and manipulate HTML elements through the DOM object and Element instances.
- [Tutorial](/docs/Tutorial/): A short, example-driven tour of Io for folks who already know how to program. Each section is a quick REPL session.

## FAQ

- [FAQ](/FAQ/): Common questions about Io — its origins, philosophy, and practical use.

## Timeline

- [Timeline](/Timeline/): Milestones in Io's history, from 2002 to today.