# Introduction

> What this site covers and how to read it.

GPUI is the GPU-accelerated UI framework behind the Zed editor. DeltaQ builds
its agentic development tools, Rexa and Zedra, on it.

This site has two jobs:

1. Teach the GPUI concepts a DeltaQ developer needs before writing a view,
   without reading Zed's source first. Start with [Getting started](/getting-started)
   and read the Concepts chapters in order.
2. Explain how [our fork](/fork/conventions) of GPUI works: how it stays in
   step with Zed, how to pick up a Zed pull request early, and how to send our
   own changes back.

The Upstream reference chapters are Zed's own GPUI documentation, included
unchanged from the vendored source so they are always current.