WebAssembly (Wasm) is a portable bytecode format that allows programming languages like C and C++ to run in web browsers with improved performance compared to JavaScript. It was first announced in June 2015, with major browser support achieved by March 2017, enabling a more efficient sandboxed execution environment. Wasm aims to address JavaScript's limitations and provide a rapid loading experience for web applications, particularly for heavy applications like games.

1. WebAssembly (WASM)
An Introduction
April 1, 2017
Brad Beiermann

2. The winner is... #3
The new logo was selected in February 2017 in a design contest
https://github.com/WebAssembly/design/issues/980

3. What is WebAssembly?
WebAssembly is a portable byte code format that has become available to the major
browsers by Google, Microsoft, Mozilla and Apple.

4. History
June 2015 - WebAssembly was first announced.
March 2016 - Google, Microsoft, Mozilla preview WebAssembly in their
browsers.
October 2016 – WebAssembly becomes a binary release candidate.
March 2017 – Begins to be shipped on-by-default in browsers.
Links of Interest:
http://webassembly.org/
https://github.com/WebAssembly
https://www.w3.org/community/webassembly/

5. Why would I need WebAssembly?
• For those of you have been looking to get binary level
support across the entire web platform stack,
WebAssembly is your ticket.
• WebAssembly is actually a binary AST format by
default.
• It is quite a departure from the payload restraints of
JavaScript.

6. The Binary Beat
• AST- Abstract Syntax Tree.
• In a compiler the AST keeps source location information
and some typing information.
• WebAssembly code essentially gets compiled to binary
AST from languages like C, Haskell, or C++ in the
browser.

7. The Advantage
• The power is being able to use other languages to compile a binary file to be
handled within the browser.
• In WASM, you can author and debug in a text format so it’s readable. We are
talking a new low-level language in the spirit of something like assembly
language.

8. Assembly Language?...Ugh! :-(

9. ...but, doesn't asm.js do this today?
• A snippet of some asm.js code.
• asm.js is a low-level subset of javascript. It appears to be direct memory register
access, but it is still being parsed by JavaScript.
• You still have all that payload overhead
• WebAssembly is bypassing all that by directly using the AST in a binary format.

10. JavaScript's Bottleneck
• JavaScript has quite a few restrictions in it’s flexibility (ie. Payload,..etc.)
• WASM works at the bare metal memory layer in the browser.
• Think about expressing things directly to threads and SIMD.
• WASM is filling in the holes left by JavaScript in terms of controlling bit/byte level
memory register control.
• You simply cannot get to that low-level with JavaScript or any other popular
library/framework in JavaScript like REACT, Angular, Embers, Vue,...etc.
BUT, one excitement around WASM is...

11. Other languages running in the browser!
"A user can compile a program of a high-level language to WebAssembly and run it
in a browser. As a first step, in the minimal viable product, the goal was to ensure
that a C/C++ program could be compiled to WebAssembly and run within the
browser."
B. Abhijith Chatra,
Sr. Software Engineer at Microsoft
Co-chairman of WASM community group

12. Up Next: Browser Compilers & Browser VMs
• They also want it to enable other programming
languages to compile efficiently to the Web.
• Again, WASM is giving you a binary executable format to
make this happen
• WebAssembly will feature a memory-safe, sandboxed
execution environment. It would access browser
functionality through the same Web APIs accessible
from JavaScript.

13. For WebAssembly to succeed we need two things:
1. Browsers to support WebAssembly natively
2. Compilers that emit WebAssembly. There are
already several out: LLVM, ilwasm, Binaryen
(written in C++), asm2wasm, Emscripten

14. Compiling a WASM Program
Step #1: Get the Emscripten Compiler and Emscripten SDK
Step #2: Enter the Emscripten compiler environment in the current
command line prompt type

15. Compiling a WASM Program (continued)
Step #3: Create a simple “hello world” program and compile it. The
compilation step is the last line.
Step #4: We can use the emrun web server provided with the
Emscripten SDK:

16. Online demo of a WASM compiler
Cross Browser Demo of Tanks (FUN!)
Some Online Demos of WASM Running
https://kripken.github.io/talks/wasm.html#/11
http://webassembly.org/demo/

17. What about mobile with WASM?

18. Where is WASM first headed?
"Rather than kill JavaScript, which is not feasible, what [we're] trying to do is respond to
real engineering problems that we’ve had with ASM.js. Loading a big game from Epic or
Unity can take 20 - 30 seconds. That’s too long. With a compressed abstract syntax tree
encoding that’s 20 times faster, just a couple seconds, that’s what you want. So there’s a
real reason for WASM, and it is a valid reason."
Brendan Eich
Author of JavaScript