BRAT is a widely used web-based text annotation tool. However, it lacks robust Python support for effective annotation management and processing. We present Bratly, an open-source extension of BRAT that introduces a solid Python backend, enabling advanced functionalities such as annotation typings, collection typings with statistical insights, corpus and annotation handling, object modifications, and entity-level evaluation based on MUC-5 standards. These enhancements streamline annotation workflows, improve usability, and facilitate high-quality NLP research. This paper outlines the system’s architecture, functionalities and evaluation, positioning it as a valuable BRAT extension for its users. The tool is open-source, and the NLP community is welcome to suggest improvements.

Natural language processing (NLP) applications such as named entity recognition (NER) for low-resource corpora do not benefit from recent advances in the development of large language models (LLMs) where there is still a need for larger annotated datasets. This research article introduces a methodology for generating translated versions of annotated datasets through crosslingual annotation projection and is freely available on GitHub (link: https://github.com/JamilProg/crosslingual_bert_annotation_projection). Leveraging a language agnostic BERT-based approach, it is an efficient solution to increase low-resource corpora with few human efforts and by only using already available open data resources. Quantitative and qualitative evaluations are often lacking when it comes to evaluating the quality and effectiveness of semi-automatic data generation strategies. The evaluation of our crosslingual annotation projection approach showed both effectiveness and high accuracy in the resulting dataset. As a practical application of this methodology, we present the creation of French Annotated Resource with Semantic Information for Medical Entities Detection (FRASIMED), an annotated corpus comprising 2’051 synthetic clinical cases in French. The corpus is now available for researchers and practitioners to develop and refine French natural language processing (NLP) applications in the clinical field (https://zenodo.org/record/8355629), making it the largest open annotated corpus with linked medical concepts in French.