WebAssembly (Wasm) is a binary instruction format for a stack-based virtual machine that allows deployment of web and server applications. Wasm is not a transpiling target for JavaScript or a replacement for JS, but rather a compilation target for programming languages to enable deployment on the web. The key aspects of Wasm include its stack-based architecture, core data types like integers and floats, control flow constructs, and use of linear memory. WABT is a toolkit that helps manipulate Wasm files, allowing generation of text format (wat) from binary (wasm) and vice versa. Building a Wasm app involves understanding its architecture and using tools like WABT.

1. Presented By: Aman Verma
WebAssembly
Fundamentals

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3. Our Agenda
01 Introduction
02 Understanding Wasm
03 WebAssembly Architecture
04 WABT
05 Building a WebAssembly Application

4. Introduction
WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual
machine. Wasm is designed as a portable compilation target for programming languages,
enabling deployment on the web for client and server applications.
● Binary instruction format
● Stack based virtual machine
● Deployment for web and server application
The key points of this definition are -

5. Understanding Wasm

9. Virtual Machine

10. JVM
Java Byte code
Java code Processor

11. Stack based VM
WebAssembly code
Rust code Web Browsers

13. What WebAssembly is not
● A transpiling target for JavaScript
● A replacement for JS
● A Programming Language
WebAssembly is not

14. Understanding WebAssembly
Architecture
1. Stack Machine

15. 2. Data Types
i32 32-Bit Integer
i64 64-Bit Integer
f32 32-Bit Floating-Point Number
f64 64-Bit Floating-Point Number
● No intrinsic signedness of data types
● There are signed and unsigned version of
operators.
Example-
i32.add and i32.add_u.

16. 3. Control Flow

17. 4. Linear Memory
● WebAssembly has linear memory
● The host can read and write any linear memory given to a Wasm module at any time, the
Wasm module can never access any of the host’s memory
Variables

18. WABT
WABT is an abbreviation for WebAssembly Binary Toolkit. It has a set of
command-line tools that helps us to manipulate WebAssembly files like generating
wat file from wasm file or creating wasm file from wat file and much more.
The two main binaries are -
● wasm2wat
● wat2wasm

19. Building a WebAssembly Application

20. Thank You !