Guides

SpiderMonkey Build Documentation: How to get SpiderMonkey source code, build it, and run the test suite.

Introduction to the JavaScript shell: Documentation of the command-line JavaScript shell, js.
JSAPI User Guide: This guide provides an overview of SpiderMonkey and describes how you can embed engine calls in your applications to make them JavaScript-aware.
JSAPI cookbook: Shows the JSAPI translation of some commonly used JavaScript expressions and statements.
GC Rooting Guide: Guide on how to write code compatible with the Generational GC in SpiderMonkey.
How to embed the JavaScript engine: An older tutorial about embedding SpiderMonkey.

Hacking on SpiderMonkey

New to SpiderMonkey: A guide to hacking on SpiderMonkey.
Setting up CDT to work on SpiderMonkey: How to configure Eclipse to work on the SpiderMonkey code.
Contributing to SpiderMonkey (YouTube): A video that is less than four minutes long.

JSAPI Reference: SpiderMonkey API reference.
JS Debugger API Reference: API reference for the Debugger object introduced in SpiderMonkey 1.8.6, which corresponds to Gecko 8.0 {{ geckoRelease("8.0") }}.
Bytecode descriptions: Listing of SpiderMonkey's bytecodes.
Parser API: Reflection of the SpiderMonkey parser, made available as a JavaScript API.

Future Directions: Future directions for functionality, design, and coding practices.
SpiderMonkey Internals: A design overview and a file-by-file walkthrough of the implementation.
Bytecode Reference: SpiderMonkey bytecode reference.
SpiderMonkey Internals: GC: Separate internals article on the GC
SpiderMonkey Internals: Hacking Tips: Collection of helpful tips & tools for hacking on the engine

SpiderMonkey release notes: Current and past versions: 52, 45, 38, 31, 24, 17