Earthly is an open-source build automation tool that simplifies the development and deployment process for Python projects by addressing common challenges such as dependency management, environment consistency, and build speed. Originally created to tackle the complexities of managing dependencies across various environments, Earthly enables developers to isolate dependencies, ensure consistent builds, and deploy applications seamlessly across multiple platforms. It integrates easily with CI/CD platforms, allowing for localized debugging of CI processes, and handles multi-language projects by providing a unified build process. Its caching mechanism accelerates the build process, making it particularly beneficial for larger projects. Earthly's containerization approach alleviates the "it works on my machine" problem, and its language-agnostic nature supports projects that require interactions with different programming languages. This tool has become essential in streamlining Python projects as they grow in complexity, offering consistency, speed, and ease of management, especially in team settings. Its founder, Vlad A. Ionescu, has developed Earthly to improve build processes and has built a company around it, highlighting its significance in modern software development.