How does visual web WYSIWYG editor works?

Question

I've seen some editors doing the same as Dreamweaver but on the Internet, how is that done is what I'd like to know. What technologies are involved?

Exemples: visualwebsiteoptimizer.com and optimizely.com

Answer 1

Maybe you could provide an example website you use.

Answer 2

It is mainly javascript

Answer 3

Those are called web apps. See: Writing web applications.