Such a strange comment to read ... quite literally, the reason I first started using Vue over other frameworks was I wanted to put it into legacy apps and did not want to use a build tool. It's one script tag. Not in a half lying way like people say about React, for real. It falls down if you start throwing in components and libraries that presume webpack based setups (which is annoying), but Vue itself is completely and trivially usable with zero build step.

Such a strange comment to read ... literally, the reason Facebook first started creating React was they wanted to put it into legacy apps. :D

literally in their docs they have you <script src> into a plain HTML file to get started. and it's not like react doesn't the same issue - hell CRA had to be built.

Version with debug enabled:

     <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>

Production version:

    <script src="https://cdn.jsdelivr.net/npm/vue"></script>

If you need something more complex, vue-cli has webpack inbuilt:

    vue init webpack my-project
    cd my-project
    npm install
    npm run dev

Or if you need webpack, but not the complexity, swap the word 'webpack' in the above command to 'webpack-simple'.

... Vue has already done the hard work of getting the build apps configured for you.

I don't follow. How to use Vue's single-file component if you only load Vue from a script tag? And can I use Brunch instead of Webpack if I want to use single-file components?

Vue's single file components (SFC) require a build tool such as Webpack or Browserify. See https://vuejs.org/v2/guide/single-file-components.html

> And can I use Brunch instead of Webpack if I want to use single-file components?

Probably, but Vue only officially supports Webpack or Browserify.

Vue also has a graphic interface now, try `vue ui`

this is really weird, not sure what you are doing...... one of the nice things about vue is it's super easy to just add to any page, I've done that a lot with transitioning pages from a mish mash of javascript to vue embedded on the page.

One time I have to maintain my own version of a vue plugin because it uses es6 syntax and I am not able to use it in no build process vue setup. Afterwards i switch to use vue cli.

My experience as well.