"Moonlight (runtime)" is a technical book that focuses on the free and open-source implementation of the Silverlight web application framework. Silverlight was originally developed by Microsoft, and Moonlight is being further developed as part of the Mono project. The book provides a comprehensive analysis of the development and features of Moonlight, including the various versions that have been released since its introduction. The first version of Moonlight was released on January 20, 2009, followed by the second version on December 17, 2009. This work is aimed at professionals and enthusiasts who wish to gain a deeper understanding of the technology behind Silverlight and its open-source alternatives. It is a valuable resource for developers working with web applications and their frameworks.