spaCy - spaCy is a library for advanced natural language processing in Python and Cython.
Amazon Comprehend - Discover insights and relationships in text
NLTK - NLTK is a platform for building Python programs to work with human language data.
Google Cloud Natural Language API - Natural language API using Google machine learning
Microsoft Bing Spell Check API - Enhance your apps with the Bing Spell Check API from Microsoft Azure. The spell check API corrects spelling mistakes as users are typing.
OpenNLP - Apache OpenNLP is a machine learning based toolkit for the processing of natural language text.