Intro: Why Build Your Own IDE? There are countless reasons to create your own IDE. Perhaps you are creating a sandbox similar to CodeSandbox, but adapted to your own framework. Or an Arduino-style environment where a strictly controlled user interface is required for flashing firmware and interacting with hardware. Maybe your SaaS product needs a built-in cloud editor. Maybe you're creating an educational platform where users should only see part of the code. Or you're releasing your own language or framework, and want the developer tools not to look like an add-on plugin. Or maybe you've decided to create your own Cursor with an AI assistant. Whatever your goal, creating your own IDE is more than possible. In this guide, I'll show you how to do it with Eclipse Theia: a fully modular, open-source platform designed to adapt to your needs.