prose is a natural language processing library (English only, at the moment) in pure Go. It supports tokenization, segmentation, part-of-speech tagging, and named-entity extraction. Parses English text, can also natively extract e-mail addresses, hashtags, @mentions, URLs, and emoticons. Can tag segmented and analyzed text by part of speech, including punctuation marks. Can identify types of entities (people, places). Also has the option to build and train custom models.