Useful links

The Code team put together this list of links to get up and running with VSCode's sourcecode. We hope it's helpful!

Contributing

How VSCode's sourcecode is organized - this explains where the entry point files are, what browser/ and common/ mean, etc. This is the most important read on this whole list! We recommend reading the whole thing.
Built-in VSCode styles - CSS variables that are built into VSCode. Use var(--vscode-{theme but replacing . with -}). You can also see their Webview theming guide.

Beginners / Getting started

VSCode UI guide - covers auxbar, panels, etc.
UX guide - covers Containers, Views, Items, etc.

Misc

Every command built-in to VSCode - not used often, but here for reference.

VSCode's Extension API

Code is no longer an extension, so these links are no longer required, but they might be useful if we ever build an extension again.

Files you need in an extension.
An extension's package.json schema.
"Contributes" Guide - the "contributes" part of package.json is how an extension mounts.
The Full VSCode Extension API - look on the right side for organization. The bottom of the page is easy to miss but is useful - cancellation tokens, events, disposables.
Activation events you can define in package.json (not the most useful).