Elm

1. Core Language

   Values, functions, lists, tuples, and records.

2. Types

   Type annotations, custom types, and pattern matching.

3. The Elm Architecture

   Model, view, and update.

4. User Input

   Handling buttons, text fields, and forms.

5. Commands and Subscriptions

   HTTP, JSON, random, time, and effects.

6. JSON Decoding

   Decoding JSON from servers.

7. Error Handling

   Maybe and Result types.

8. Interop with JavaScript

   Flags, ports, and custom elements.

9. Web Apps

   Single-page apps, navigation, and URL parsing.

10. Optimization

    Lazy rendering, asset size, and keyed nodes.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.