spaCy - spaCy is a library for advanced natural language processing in Python and Cython.
Tesseract - Tesseract is an optical character recognition engine for various operating systems
Google Cloud Natural Language API - Natural language API using Google machine learning
Onlineocr.net - Free Online OCR service allows you to convert PDF document to MS Word file, scanned images to editable text formats and extract text from JPEG/TIFF/BMP files
monkeylearn - Text Mining Made Easy. Extract and classify information from text. Integrate with your App within minutes.
Prizmo - Prizmo is a scanning application for Mac with Optical Character Recognition (OCR) in over 40 languages with powerful editing capability, text-to-speech, and iCloud support.