If you want to use JavaScript, sure, a small pop-up is one option.

If you don't, target is what you have.

Suppose you have explanatory/reference text a new user may want to see, but which would be mere visual clutter to an experienced user. Definitions of terminolgy, syntax reference, that sort of thing. Opening it in a new window allows the user to switch between the two easily.

I've rarely, if ever, used target="_new" or target="_blank" on a general audience public site. I have used it on specialized internal tools, where it is necessary for the user to compare content the current page to that in the new window.