Bringing WebAssembly to the .NET Mainstream - Steve Sanderson, Microsoft

Many developers still consider WebAssembly to be a leading-edge, niche technology tied to low-level systems programming languages. However, C# and .NET (open-source, cross-platform technologies used by nearly one-third of all professional developers [1]) have run on WebAssembly since 2017. Blazor WebAssembly brought .NET into the browser on open standards, and is now one of the fastest-growing parts of .NET across enterprises, startups, and hobbyists. Next, with WASI we could let you run .NET in even more places, introducing cloud-native tools and techniques to a wider segment of the global developer community. This is a technical talk showing how we bring .NET to WebAssembly. Steve will demonstrate how it runs both interpreted and AOT-compiled, how an IDE debugger can attach, performance tradeoffs, and how a move from Emscripten to WASI SDK lets it run in Wasmtime/Wasmer or higher-level runtimes like wasmCloud. Secondly, you'll hear lessons learned from Blazor as an open-source project - challenges and misconceptions faced bringing WebAssembly beyond early adopters. [1] StackOverflow survey 2021 

This is a (non-comprehensive) guide for C# and .NET developers that are completely new to the Rust programming language. Some concepts and constructs translate fairly well between C#/.NET and Rust, but which may be expressed differently, whereas others are a radical departure, like memory management. This guide provides a brief comparison and mapping of those constructs and concepts with concise examples. 

#Script is a simple, fast, highly versatile and embeddable scripting language for .NET Core and .NET Apps that utilizes a familiar JavaScript inspired expressive Syntax to enable dynamic scripting of .NET Apps via controlled access to pluggable methods and arguments within a sandbox environment - ensuring scripts are encapsulated and encourages the use of reusable and testable components where live environments can be easily re-created and simulated.  

Here are some of the reasons why nullable reference types are less than ideal:

• Invoking a member on a null value will issue a System.NullReferenceException exception, and every invocation that results in a System.NullReferenceException in production code is a bug. Unfortunately, however, with nullable reference types we “fall in” to doing the wrong thing rather than the right thing. The “fall in” action is to invoke a reference type without checking for null.
• There’s an inconsistency between reference types and value types (following the introduction of Nullable<T>) in that value types are nullable when decorated with  “?” (for example, int? number); otherwise, they default to non-nullable. In contrast, reference types are nullable by default. This is “normal” to those of us who have been programming in C# for a long time, but if we could do it all over, we’d want the default for reference types to be non-nullable and the addition of a “?” to be an explicit way to allow nulls.
• It’s not possible to run static flow analysis to check all paths regarding whether a value will be null before dereferencing it, or not. Consider, for example, if there were unmanaged code invocations, multi-threading, or null assignment/­replacement based on runtime conditions. (Not to mention whether analysis would include checking of all library APIs that are invoked.)
• There’s no reasonable syntax to indicate that a reference type value of null is invalid for a particular declaration.
• There’s no way to decorate parameters to not allow null. 

Modular Web Application with ASP.NET Core  

Internet Information Services (IIS) 10.0 Express is a free, simple and self-contained version of IIS that is optimized for developers. IIS 10.0 Express makes it easy to use the most current version of IIS to develop and test websites. IIS 10.0 Express has all the core capabilities of IIS 10.0 and additional features to ease website development.

The benefits of using IIS 10.0 Express include:

• The same web server that runs on your production server is now available on your development computer.
• Most tasks can be done without the need for administrative privileges.
• IIS Express runs on Windows 7 Service Pack 1 and all later versions of Windows.
• Many users can work independently on the same computer. 

The core of the Dictionary type is a standard hashtable, straight out of an algorithms book. However, it’s interesting design comes from how it deals with hash collisions, using a variant of chaining  

- .NET Core
- Node.js
- Docker
- Elasticsearch: A distributed and open source search engine based on Lucene. A blazing fast NoSQL database with replication capabilities, it is the most widely known component of the ELK stack, together with Kibana (for reporting and visualizations), Logstash (for data import) and Beats (for data shipping). Even Azure Search uses it behind the covers. Free but some tools are paid. Get it from http://elastic.co.
- ECMAScript 2015
- HTML5
- Kafka
- TypeScript
- MongoDB
- Git
- Nginx
- Octopus Deploy
- Azure
- Amazon Web Services
- Linux
- Visual Studio Code
- Xamarin
- Google Analytics
- SQL Server 2016
- Let’s Encrypt
- TensorFlow
- GitLab
- Redis 

Today, we’re announcing .NET Core 3.0 Release Candidate 1. Just like with Preview 9, we’ve focused on polishing .NET Core 3.0 for a final release. We are now getting very, very close. We intend to release the final version on September 23 at .NET Conf.