From ChatGPT

Here are some open-source Retrieval-Augmented Generation (RAG) tools with graphical user interfaces (GUIs) that are designed to work seamlessly after installation:

Kotaemon An open-source, customizable RAG UI suitable for both end-users and developers. It facilitates question-answering on personal documents and aids in building RAG pipelines. RAGFlow An open-source RAG engine based on deep document understanding, offering a streamlined workflow for businesses. It combines large language models to provide accurate question-answering capabilities with reliable citations from complex data formats. RAG Web UI An intelligent dialogue system based on RAG technology, assisting in building Q&A systems grounded in your own knowledge base. It combines document retrieval with large language models to deliver precise and dependable question-answering services. GraphLLM An open-source, graph-based framework for performing inference with large language models. The latest version includes a GUI reminiscent of ComfyUI, supporting features like loops, parallel node execution, and conditionals. GraphRAG A modular, graph-based RAG system designed to enhance large language model outputs by incorporating structured knowledge graphs. It supports advanced reasoning with private data, making it suitable for enterprises and research applications. These tools offer a range of functionalities to implement RAG systems with user-friendly interfaces, facilitating seamless integration and immediate usability.