Folks here might be interested in WebAssembly from the Ground Up (https://wasmgroundup.com) — an online book to learn Wasm by building a simple compiler in JavaScript. (Disclaimer: I'm one of the authors.)
So far the book only covers WebAssembly 1.0 though. We'll likely publish an update to cover the (few) new features in 2.0, but WebAssembly 3.0 is a pretty big update. Garbage collection and typed references especially add quite a lot to the spec. But, they also make a lot more things possible, which is great.
The spec itself is also very readable and accessible. Everything in the spec that's described formally is also described in plain language. I can't think of any other spec that's quite as nice to read.
So far the book only covers WebAssembly 1.0 though. We'll likely publish an update to cover the (few) new features in 2.0, but WebAssembly 3.0 is a pretty big update. Garbage collection and typed references especially add quite a lot to the spec. But, they also make a lot more things possible, which is great.
The spec itself is also very readable and accessible. Everything in the spec that's described formally is also described in plain language. I can't think of any other spec that's quite as nice to read.