The text discusses setting up Deno on GitHub Codespaces using Dev Containers. It explains that Deno is a secure runtime for JavaScript and TypeScript, built with Rust, designed to address Node.js shortcomings. The author provides an example of a simple Deno script and introduces the concept of Dev Containers, which are used to define a development environment as code. The article highlights the benefits of Dev Containers, including consistent development environments, simplified onboarding, and streamlined CI/CD processes. It also mentions that GitHub Codespaces offers a flexible and efficient approach to writing, running, and debugging Deno applications directly in the browser. The author guides readers through setting up a Deno Dev Container, creating a `devcontainer.json` file, and configuring VS Code extensions for Deno development. Additionally, it discusses the importance of code security with Snyk and recommends several VS Code extensions for Deno development, including TypeScript Hero, TSLint, and Prettier.