AllenNLP is an open-source Python library for natural language processing research, developed by the Allen Institute for AI on top of PyTorch. It provided ready-made components and models for tasks such as text classification, coreference resolution and question answering. Since late 2022 AllenNLP has no longer been actively developed and is in maintenance mode; its maintainers point to alternatives such as AI2 Tango, flair or Hugging Face Transformers (as of October 2026).
Natural language processing is the branch of AI that enables computers to analyse, understand and generate human language in text or speech. It covers tasks such as translation, classification, summarisation, sentiment analysis and question answering. Rules and statistical methods once dominated; today the field is shaped by large language models.
PyTorch is an open-source framework for machine learning and deep learning in the Python programming language. It was originally developed at Meta (then Facebook) and has been stewarded since 2022 by the PyTorch Foundation under the umbrella of the Linux Foundation. PyTorch is widely used in research and industry because it lets developers build models flexibly, train them on GPUs and test them step by step; many well-known language and image models are built with it.
Hugging Face Transformers is an open-source Python library that gives access to pre-trained models for text, images and audio through a single, consistent interface. Developers use it to download models from the Hugging Face Hub, try them out, adapt them to their own data or run them locally. Since version 5 the library has focused primarily on PyTorch (as of October 2026). Example: a team tests a sentiment-analysis model with just a few lines of code.
spaCy is an open-source Python library for natural language processing, developed by the Berlin-based company Explosion. It splits texts into words and sentences, determines parts of speech and base forms, analyses sentence structure and recognises named entities such as people, companies or places. Pre-trained models are available for many languages, including German. spaCy is designed for speed and for use in real applications, for example to pre-process large volumes of documents.
