An accessible guide for beginner-to-intermediate programmers to the concepts, real-world applications, and latest features of C# 13 and .NET 9, with hands-on exercises using Visual Studio and Visual Studio CodeKey FeaturesExplore the newest additions to C# 13, the .NET 9 class libraries, and Entity Framework Core 9Build professional websites and services with ASP.NET Core 9 and BlazorEnhance your skills with step-by-step code examples and best practices tipsBook DescriptionThis Packt bestseller continues to be the definitive guide to modern cross-platform development. The 9th edition of C# 13 and .NET 9 – Modern Cross-Platform Development Fundamentals has been updated to cover the latest features and improvements in .NET 9 and C# 13. You'll start by mastering object-oriented programming, learning how to write, test, and debug functions, and implementing interfaces. You'll then dive into .NET APIs for data management, filesystem operations, and serialization. This latest edition integrates .NET 9 enhancements into its examples: faster exceptions and new LINQ methods. New ASP.NET Core 9 features include optimized static assets, built-in OpenAPI document generation, and the HybridCache. Practical examples, such as building websites and services with ASP.NET Core, have been refreshed to utilize the latest .NET 9 features. The book also introduces Blazor, with its new unified hosting model for unparalleled code reusability. With these updates, you'll learn how to build robust applications and services efficiently and effectively. By the end of this book, you'll have the knowledge and confidence to create professional and high-performance web applications using the latest technologies in C# 13 and .NET 9.What you will learnDiscover the new features of .NET 9, including more flexible params and new LINQ like CountBy and IndexLeverage the new ASP.NET Core 9 features for optimized static assets, OpenAPI document generation, and HybridCacheUtilize the native AOT publish capability for faster startup and reduced memory footprintBuild rich web user interface experiences using Blazor in ASP.NET Core 9Integrate and update databases in your applications using Entity Framework Core 9 modelsQuery and manipulate data using LINQBuild powerful services using Minimal APIsWho this book is forThis book is aimed at beginner to intermediate-level C# and .NET developers. While prior exposure to C# or .NET is not a prerequisite, a general understanding of programming concepts will be beneficial. If you want to learn more technologies for building modern .NET projects like gRPC, SignalR, and .NET MAUI, read Mark's Apps and Services with .NET 8 book next; and if you aim to become a professional .NET developer quickly or mainly work on team projects, read his other book, Tools and Skills for .NET 8.