# The Shell

Serena OS comes with a powerful shell that allows you to run applications, work with files, directories, expressions and to write and execute scripts. Contrary to traditional shell languages, the Serena shell language is a fully formally defined language which features expressions, a formally defined type system, scoping, immutable and mutable variables, flow control constructs and a large array of builtin commands.

See the chapters below for more information about various shell topics.

## Introduction

* [Quick Tour](docs/QuickTour.md)
* [Line Editor](docs/LineEditor.md)

## The Language

* [Introduction](docs/Language.md)
* [Expressions](docs/Expressions.md)
* [Variables](docs/Variables.md)
* [Control Flow](docs/ControlFlow.md)
* [Scripts](docs/Scripts.md)

## Commands

* [Commands](docs/Commands.md)
* [Operators](docs/Operators.md)

## Design Documentation

* [Tokens](docs/Tokens.md)
* [Grammar](docs/Grammar.md)
* [Semantic](docs/Semantic.md)