ELF, or Extensible Language Framework, is a software framework designed to facilitate the development of applications that can be easily extended and customized. It provides a set of tools and libraries that help developers create modular applications, allowing for the integration of new features without altering the core system. This flexibility makes it popular in various programming environments. The ELF framework is often used in conjunction with Java and Eclipse, a widely-used integrated development environment (IDE). By leveraging ELF, developers can enhance their applications' functionality while maintaining a clean and organized codebase, ultimately improving efficiency and collaboration in software development projects.