Chris McCord, the creator of Elixir's Phoenix framework, introduces Phoenix.new, an innovative online coding agent tailored for Elixir and Phoenix, aimed at streamlining the development of collaborative, real-time applications. Phoenix.new operates entirely in a browser, providing an isolated virtual machine environment where developers and agents can freely install and run programs without impacting local machines. It features a headless browser to interact with applications, allowing the agent to verify changes in real-time without human intervention. The platform supports building full-stack applications and integrates seamlessly with GitHub, offering private, shareable URLs and leveraging Fly.io's infrastructure for cloud deployment. McCord envisions Phoenix.new as a pivotal shift in developer workflows, facilitating continuous iteration and collaboration, and sees its future in expanding support for additional languages and frameworks while maintaining a focus on enhancing developer productivity.