The group of Prof. George Malliaras has recently published a review article entitled “Organic electrochemical transistors” on Nature Reviews Materials. In this article, the physics and the mechanism of operation of organic electrochemical transistors (OECTs) are discussed focusing on their identifying characteristics. Organic materials that are currently being used in OECTs are identified and the history of OECT technology is surveyed. In addition, form factors, fabrication technologies and applications such as bioelectronics, circuits and memory devices are examined. Finally, a critical look at the future of OECT research and development is presented.