An open-source tool named Kotaemon has emerged as a leading resource for document question answering (QA), trending at number one on GitHub. Built with Gradio, Kotaemon allows users to host their own Document QA Web-UI, organize large language models (LLMs) and embedding models, and implement a hybrid retrieval-augmented generation (RAG) pipeline. The tool supports both local LLMs and API providers, offering advanced features such as customizable user interfaces, detailed citations, and multi-user hosting capabilities. Additionally, it incorporates multi-modal QA, enhancing the user experience by enabling users to interact with documents in various formats. The tool's popularity highlights the growing interest in RAG systems, which utilize external knowledge to improve LLM performance, although challenges such as complex reasoning and domain expertise remain prevalent.