What is a WebAssembly (Wasm)?

Purpose of WebAssembly

WebAssembly was created as a response to the performance limitations of JavaScript in web browsers, especially for computationally complex tasks such as 3D games, video editing, scientific simulations and computationally intensive applications. The goal was to create a secure, fast, portable and efficient binary format that could run alongside JavaScript, allowing code written in other languages to run in the browser.

Key features of WebAssembly

• Performance: Wasm code is optimized for fast parsing and execution by browsers, achieving performance close to native (much faster than interpreted JavaScript in many cases).
• Portability: Wasm’s binary format is independent of the hardware platform and operating system, allowing it to run in a variety of environments that support the standard.
• Security: WebAssembly modules run in a secure, isolated environment (sandbox) in the browser, with limited access to operating system resources, which protects the user from malicious code.
• Compactness: The binary format is usually more compact than the corresponding JavaScript code.
• Multi-language support: source code written in various languages (C, C++, Rust, Go, C#, AssemblyScript, etc.) can be compiled into Wasm format using appropriate tools (e.g. Emscripten, Binaryen).
• Interoperability with JavaScript: WebAssembly modules can be easily loaded and called from within JavaScript code, and can call JavaScript functions. This allows Wasm to be phased into existing web applications and used to optimize performance-critical portions of code.

Applications of WebAssembly

WebAssembly opens up new possibilities for web applications and more:

• Powerful web applications: Create 3D games, graphics and video editors, CAD tools, simulations that run seamlessly in the browser.
• Porting of existing applications: Porting existing desktop applications written in C/C++ or other languages to a web environment.
• Libraries and frameworks: Create high-performance libraries (e.g., for computing, cryptography, image processing) that can be used both in the browser and on the server side.
• Server-side Wasm applications: Running Wasm code on the server side (e.g., in serverless environments, as plug-ins to proxy servers) for security, portability and performance.
• Embedded systems and IoT: Using Wasm as a secure and portable runtime format on resource-constrained devices.

The future of WebAssembly

WebAssembly is still a rapidly evolving standard. Work is underway to add new features such as threading support, garbage collection (GC), direct access to the DOM (Document Object Model) or system interfaces (WASI – WebAssembly System Interface) that will further expand its capabilities and applications beyond the browser.

Summary

WebAssembly is a breakthrough technology that enables code compiled from various programming languages to run in browsers with near-native performance. It complements JavaScript, opening the door to the development of more complex and computationally intensive web applications and finding increasing use also on the server side and in other environments.