A leading platform for building Python programs to work with human language data.
spaCy is built for production pipelines: fast tokenization, part-of-speech tagging, dependency parsing and named entity recognition, with trained pipelines for many languages and a clean way to add custom components. NLTK is the teaching and research toolkit, with corpora, lexical resources and classic algorithms that are easy to inspect. Stanza, from the Stanford NLP Group, provides neural pipelines across a wide range of languages with accurate syntactic analysis. Gensim focuses on topic modeling and word vectors (LDA, word2vec) and streams large corpora without loading them into memory.
General4
A library for industrial-strength natural language processing in Python and Cython.
The Stanford NLP Group's official Python library, supporting 60+ languages.
Chinese4
OpenCCC++ core
Traditional/Simplified Chinese conversion with regional variants and phrase-level rules.