Dokku is a lightweight, open-source Platform as a Service (PaaS) that allows developers to easily deploy and manage applications on their own servers. Built on top of Docker, Dokku leverages containerization to provide a simple Heroku-like experience, enabling users to deploy apps using git push commands. It supports multiple languages and frameworks, and offers plugin extensibility for adding features like databases, caching, and more. Dokku is ideal for developers and teams looking for a cost-effective, self-hosted solution to manage app deployments with minimal overhead and full control over their infrastructure.