Installing - Recommended and alternative installation mechanisms.
Quick start - Where to begin after you've installed WP-CLI for the first time.
Commands cookbook - The full 101 how commands work, writing your own, and sharing them with the world.
Common issues and their fixes - In case of fire, break glass.
External resources - Blog posts, slides and videos from users.

Global parameters - Variables defining how a command is executed, including which WordPress user the command is run as and which WordPress instance the command is run against.
Built-in commands - Commands included in every copy of WP-CLI.
Package index - Commands maintained and supported by the community.
Internal API - Stable utilities considered safe to use in community commands.
Documentation Standards - Standards for annotating WP-CLI commands.
Hosting companies - List of hosting companies where WP-CLI is installed by default.
Shell friends - Helpful shortcuts for bash and zsh.
Integrated tools - Plugins, wrappers, and other projects that integrate with WP-CLI in some form.

Bug reports - Help ensure your issue is resolved in a timely manner.
Contributing - An introduction to the contributing process.
Governance - Summary of those behind WP-CLI.
Implementation details - Catalog of historical design decisions.
Philosophy - Guidelines which inform project scope, command organization, and behavior.
Pull Requests - Submit your first bug fix or new feature.
Release checklist - Tasks performed during the process of tagging a release.
Roadmap - Where WP-CLI is going in the future.

Plugin unit tests - How to set up and run PHPUnit tests for a WordPress plugin.
Website and Package Index wish list - A list of ideas and potential improvements for wp-cli.org