Let's say my website heavily depends on JavaScript.
I found this: http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_noscript
What I understand is.

If JavaScript is enabled, it displays "Hello World". If JavaScript is disabled it displays everything within <noscript> as normal div.

The clue is. I have "NoScript" Firefox addon. That blocks JavaScripts, disables flashes and fonts. And if I want to view YouTube video for example I need to click on frame of video. But when I visited the example on link above. Nothing happened. The result is nul literally. Nothing is there.

Are there any other solutions, that are more universal?

Are there any other solutions, that are more universal?

You can add a text div that is visible, and remove it with Javascript. If Javascript is not enabled, it will not be removed.

@pritaeas, that seems like good idea. But wouldn't it be that user could easily remove that visible DIV? I need to assume visitors are pesky.

You have no control over the browser or browser plugins, so there's no way to guarantee visibility for all users.