Duolingo is a technology company, engaged in providing language-learning website and mobile app, as well as a digital language proficiency assessment exam. Co.'s solutions include: The Duolingo Language Learning App, which provides courses in over 40 languages to users; Duolingo Plus, which provides learners additional features; Duolingo English Test: AI-Driven Language Assessment, which is an online English assessment; Duolingo for Schools, which is a web-based tool that aims to make it easier for teachers to use the Duolingo platform in a structured learning environment, like a classroom; and Duolingo ABC, which is an app that teaches children ages three to six early literacy skills.