Tesseract OCR

Optical Character Recognition

GitHub: tesseract

Per Wikipedia:

Tesseract is an optical character recognition engine for various operating systems. It is free software, released under the Apache License. Originally developed by Hewlett-Packard as proprietary software in the 1980s, it was released as open source in 2005 and development was sponsored by Google in 2006.

In 2006, Tesseract was considered one of the most accurate open-source OCR engines available.