>Except for creating an HTML-file and understanding how all that works.
Using chrome? Hit [ctrl+shift+j|cmd+option+j] and you can write JavaScript without any HTML necessary. Other browsers have similar consoles that need no HTML to write JavaScript.
Completely disagree - I write most of my production code in a REPL (either JavaScript or Python), and only save it to a file once I know it's going to work.
I'm not against using REPL, but it's not viable to solely write in REPLs, therefore we need to teach "how to run things in files" and then we're back at crappy HTML-files.
I don't see anybody saying one need to use REPLs only. What's nice with JS is you have the option to open browser's JS console and try stuff there. You don't need to. But you can.
All modern browsers has JS console. That's dev environment setup freely for you. And if you use FF, enhancing that env with Firebug is just a few clicks away. WIth the rise of web apps nowadays, this is actually a very good move.
Using chrome? Hit [ctrl+shift+j|cmd+option+j] and you can write JavaScript without any HTML necessary. Other browsers have similar consoles that need no HTML to write JavaScript.