While developing VueUse, we extract the tools we are using into separate projects that can be used standalone from time to time.
Vue Demi is a tool for library authors to create composable libraries that work for Vue 2 and 3 isomorphically just like VueUse. It has been widely adopted by many popular libraries like vuelidate and vue-promised.
Vue Chemistry utilizes the reactify function and applies it to common JavaScript APIs, which enables a pure reactive programming experience. For example:
import { set } from 'vue-chemistry/core'
import { sum } from 'vue-chemistry/math'
import * as console from 'vue-chemistry/console'
const a = ref(1)
const b = ref(2)
const c = sum(a, b) // c = a + b = 3
set(a, 2) // shorthand for a.value = 2
console.log(c) // it's 4 (2 + 2)!