Unitxt is an innovative library tailored for generative language models, specializing in customized textual data preparation and evaluation. natively integrated with popular libraries like HuggingFace and LM-eval-harness, Unitxt breaks down the processing workflow into modular components, enabling easy customization and sharing. These components include comprehensive dataset handling definitions for model-specific formats, task prompts, and more. Unitxt-Catalog centralizes these components, promoting collaboration and exploration within modern text data workflows. Beyond a tool, Unitxt is a community-driven platform, empowering users to collaborate on building, sharing, and advancing their data pipelines.