TAO, from Open Assessment Technologies, is the leading open source digital assessment solution for education and career advancement, with over 100 million test deliveries in more than 30 languages worldwide. Modular, customizable and interoperable by design, TAO empowers you to break free from the confines of proprietary silos, eliminate expensive licensing fees, take full control of your testing resources, and enjoy enterprise-level support. TAO is a commercial-grade assessment solution consisting of powerful next-generation components that can be deployed as-is, modified with new features, and integrated with other tools and administrative systems. TAO has robust tools to support the full digital assessment lifecycle but is also designed to support future innovation thanks to an extensible source code. The platform is built around an extension management engine, which allows plug-in of additional capabilities modifying existing functionality, or adding new functionality.