Fable.Extras 
A more functional construct on-top of Fable.Core.
Near-zero bundle size, as almost the entire library is erased at compile time.
Documentation can be found here.
A quick look:
JS Maps
open Fable.Extras
JSe.Map.empty<int,int>
|> JSe.Map.set 1 1
|> JSe.Map.set 2 4
|> JSe.Map.values
|> List.sum // 5JS Regular Expressions and String extensions
open Fable.Extras
let pattern = JSe.RegExp("^[0-9]")
"20 foxes jumped over the bridge".Replace(pattern, "numbers")
// "numbers foxes jumped over the bridge"Or assignment chaining
open Fable.Extras
open Fable.Extras.Operators
let maybeInt = None ?| Some 1 ?| None ?| Some 2 // Some 1Web Assembly
open Fable.Extras
open Fable.Extras.WebAssembly
// Wasm binding
type WasmFableExports =
abstract add: int * int -> int
async {
let! wasmBinary = ... // HttpResponse
return! WA.compileStreaming<WasmFableExports>(wasmBinary)
}
...
wasmInstance.add(1,2) // 3