Doccano
Doccano is an open‑source annotation platform for natural language processing (NLP) tasks. It provides a web-based user interface that enables users to label text for a variety of supervised learning problems, including named entity recognition, text classification, sequence‑to‑sequence, sequence labeling, and language generation. The project was originally released in 2018 as a fork of the web application by the University of Texas at Austin, and it is maintained under the Apache License 2.0. Doccano supports multiple file formats—such as JSON, CSV, and XML—for both input and output, which allows easy integration with existing data pipelines.
The system offers role‑based access control, allowing administrators to create and manage projects, define label sets,
Doccano is built with Django on the backend and uses the React framework for the front end,
The community contribution model is active; contributions appear in the GitHub repository under various issue trackers