Dify is an open-source Large Language Model (LLM) application development platform. It provides a suite of tools and features designed to simplify the creation, deployment, and management of AI-powered applications. One of its key features is a visual interface for designing and debugging prompts, which allows for rapid prototyping and iteration. The platform also includes a RAG (Retrieval-Augmented Generation) engine, which enables developers to build applications that can access and reason over external knowledge sources. Dify supports both commercial and open-source models, providing flexibility for a wide range of use cases. The platform is designed to be self-deployed, giving developers full control over their data and applications.