I believe wasm can run off a SharedArrayBuffer, which is mutable. I'm not sure how that interacts with the running engine, how dynamically modifiable it is. Trying to runtime rewrite wasm & figure out exports would be... complicated. But this blanket statement still comes as quite a surprise to me, even though I know that within WASM no one is able to re-write the code.

Deno has been doing a lot of work to make sure V8 Isolate's snapshots are well supported & easy to build & manage & launch. I'm very excited to see Deno, someday, post similar orders-of-magnitude wins. I expect folks like CloudFlare Workers already do this.

Web Assembly (WASM) is an official W3C standard

• Running apps on the web with close performance to native apps (i.e. Figma)
• Compile target for other languages to run on modern Browsers (.wat -> .wasm)
• Code can also be written using AssemblyScript

Official basic solidity explanation. Notice the warnings about new versions breaking old coding methods. This is very common in solidity as it is still viewed as an in development language. Solidity is expected to remain a blockchain smart contract programming standard for quite sometime while other competing languages such as Rust, Java, C++, etc are expected to gain more ground particularly due to the introduction of the WASM low level language and the toolkit that supports it which is well established and well integrated. Here's a link to some more WASM goodness. https://hackernoon.com/the-three-eggs-in-a-distributed-basket-wasm-blockchain-and-reputation-296892cdd77c

WASM is being used to run many demanding applications directly in the browser. Autocad is one important example where architects can use this application without installing a usually very heavy piece of software on their computers. They can access the Autocad suite from almost any computer only by logging into to a website. It is expected that a large part of the gaming industry will shift this way as well as many other services. One of the main advantages of this approach aside from a lack of a local installation is real-time software updates for any number of users. A new model of software building and execution will be based on WASM. WASM is also very good for blockchains. Search for the WASM section to learn more.