In this paper, a brief history of the evolution of Farsi (Persian) script is presented, including how the Farsi alphabet was derived from the Arabic alphabet. Important features, similarities and dissimilarities between Farsi and Arabic scripts, from the Optical Character Recognition (OCR) point of view are discussed. Also, a brief review of some of the state-of-the-art techniques in off-line and on-line Farsi script recognition and segmentation, as well as challenges ahead are briefly presented.