This paper reviews the advancements, challenges, and successes of synchronous languages over the past 12 years. Synchronous languages, including Esterel, Lustre, and Signal, have established themselves as a preferred technology for modeling, specifying, validating, and implementing real-time embedded applications. The paradigm of synchrony, which combines time advances with deterministic concurrency, has emerged as an engineer-friendly design method based on mathematically sound tools. The paper discusses the fundamentals of synchrony, including the need for functional and deterministic system behavior, simplicity, and the challenges of combining synchrony with concurrency. It highlights successful industrial applications of these languages, such as in safety-critical systems like flight control and automotive anti-skid systems. The authors also describe the commercialization of the languages, including the development of tools and compilers, and the integration of synchronous languages into existing design flows. New technologies for compiling synchronous languages are discussed, focusing on handling arrays and improving code generation. The paper concludes with a discussion of future challenges, including the limitations of synchrony and the need for further research to address these issues.This paper reviews the advancements, challenges, and successes of synchronous languages over the past 12 years. Synchronous languages, including Esterel, Lustre, and Signal, have established themselves as a preferred technology for modeling, specifying, validating, and implementing real-time embedded applications. The paradigm of synchrony, which combines time advances with deterministic concurrency, has emerged as an engineer-friendly design method based on mathematically sound tools. The paper discusses the fundamentals of synchrony, including the need for functional and deterministic system behavior, simplicity, and the challenges of combining synchrony with concurrency. It highlights successful industrial applications of these languages, such as in safety-critical systems like flight control and automotive anti-skid systems. The authors also describe the commercialization of the languages, including the development of tools and compilers, and the integration of synchronous languages into existing design flows. New technologies for compiling synchronous languages are discussed, focusing on handling arrays and improving code generation. The paper concludes with a discussion of future challenges, including the limitations of synchrony and the need for further research to address these issues.