In this ever growing world of IT, we have numerous different platforms, frameworks, and languages on which applications are built based on the business needs, requirements, and the developer's interest. To remove this barrier of different platforms, Microsoft came up with the fastest, latest, and greatest version of .NET, the .NET Core cross-platform open source framework. Using this framework, beginner-level developers can work on different platforms, and experienced developers and architects can consume their APIs and libraries across different platforms. This book covers simple examples of using .NET Core to build modern, internet-connected, and cloud-based applications. The book will help us develop simple yet interesting applications to provide the readers with working code examples. We will develop a Tic-Tac-Toe game to begin with, then build a real-time chat application, Lets Chat (for chatting with our online Facebook buddies), a sample chat bot, and a dummy movie booking application.