What is WebAssembly? The next-generation web platform.

Introduction

WebAssembly is a binary format that is designed to be a low-level virtual machine for executing code in the browser. It is designed to provide a more efficient and secure way to run complex applications in the browser, by allowing developers to write code in languages other than JavaScript.

WebAssembly is often used as an alternative to JavaScript for computationally intensive tasks, such as gaming, video, and image processing, and scientific simulations. With WebAssembly, developers can write code in languages like C, C++, and Rust, which are then compiled into WebAssembly modules that can be executed in the browser.

One of the key benefits of WebAssembly is its performance. Because WebAssembly is a binary format that is executed directly by the browser, it can be much faster than interpreted JavaScript code. This can lead to significant improvements in the performance of web applications, particularly those that require complex calculations or data processing.

Another benefit of WebAssembly is its security. Because WebAssembly code is executed in a sandboxed environment within the browser, it is much more secure than running native code on a user's computer. This can help to prevent security vulnerabilities and ensure that web applications are safe and secure.

Here are some examples of how WebAssembly can be used in JavaScript:

1. Gaming: WebAssembly can be used to build high-performance games that run directly in the browser. For example, the game "Cube Slam" was built using WebAssembly and WebGL.
2. Video and Audio Processing: WebAssembly can be used to speed up video and audio processing tasks in the browser. For example, the open-source video editor "Olive" uses WebAssembly to speed up video encoding and decoding.
3. Scientific Computing: WebAssembly can be used to build scientific computing applications that run in the browser. For example, the "Blazor" project uses WebAssembly to run .NET code in the browser, which can be used for scientific computing tasks.
4. Machine Learning: WebAssembly can be used to run machine learning models in the browser, allowing for fast and efficient processing of data. For example, TensorFlow.js provides a JavaScript API for running machine learning models in the browser, with the option to use WebAssembly for improved performance.
5. CAD Applications: WebAssembly can be used to build complex CAD applications that run directly in the browser. For example, the "Onshape" CAD application uses WebAssembly to provide a high-performance user interface for 3D modeling.

WebAssembly language support 

WebAssembly is designed to be language-agnostic, which means that it can be used with a variety of programming languages. Here are some of the programming languages that currently support WebAssembly:

1. C/C++: C and C++ are the most widely used languages for writing WebAssembly code. This is because the LLVM compiler, which is commonly used for compiling C/C++ code, includes support for generating WebAssembly code.
2. Rust: Rust is a systems programming language that is designed to be fast and safe. It has strong support for WebAssembly, and its compiler can generate WebAssembly code directly.
3. AssemblyScript: AssemblyScript is a subset of TypeScript that is designed to compile to WebAssembly. It is a great choice for developers who are already familiar with TypeScript and want to use it to write WebAssembly code.
4. Go: Go is a popular programming language that is commonly used for building networked and distributed systems. Its compiler can generate WebAssembly code, allowing Go developers to write applications that can run in the browser.
5. Swift: Swift is a general-purpose programming language developed by Apple. Its compiler can generate WebAssembly code, making it a good choice for building iOS and macOS applications that can also run in the browser.

Here's an example of WebAssembly code written in C that adds two integers together:

First, we need to write a C function that takes two integers and returns their sum:

int add(int a, int b) {
  return a + b;
}

Next, we need to compile this function into WebAssembly using the emcc compiler. The following command will compile the function into a WebAssembly module called add.wasm:

emcc add.c -s WASM=1 -o add.wasm

Now that we have our WebAssembly module, we can load and run it in JavaScript using the following code:

fetch('add.wasm') .then(response => response.arrayBuffer())
            .then(bytes => WebAssembly.instantiate(bytes)) .then(obj => {
            const result = obj.instance.exports.add(1, 2); console.log(result);
            // prints 3 }); 

This code fetches the add.wasm file, loads it into memory using the WebAssembly.instantiate function, and then calls the add function with the arguments 1 and 2. The result is then printed to the console.

Note that this is a very simple example, but it demonstrates the basic workflow for using WebAssembly with C. More complex programs can be compiled into WebAssembly in a similar way.

Overall, WebAssembly can be used in a wide range of applications where high-performance computation is required, making it a valuable addition to the JavaScript ecosystem. WebAssembly is an exciting development for web developers, as it opens up new possibilities for building complex and performant applications in the browser. While it is still a relatively new technology, it is likely to play an increasingly important role in the future of web development.