I use it to display RSS feeds on my personal website (https://maxbo.me) as a allusion to news tickers (which are themselves an allusion to ticker tape machines: https://en.wikipedia.org/wiki/Ticker_tape)

The correct use is alongside the “man with a spade”.jpg to let people know your page is under construction.

"Hey! Stickly Man! WHAAAAAAAAAAAT are you doing!"

https://homestarrunner.com/toons/under-construction

I use a bunch of marquees to create an animated scene on my homepage[0]. Different speeds for a parallax effect and even some multi-axis marquees for rain effect.

[0]: https://bradlyfeeley.com/ (no idea which browsers it renders properly in)

I love the use of emoji in that animated scene! I would never have guessed; I only found out from looking at the raw HTML.

Trees and clouds! (Pixel + Chrome)

Plex does something very similar to marquee to display an actors name when it's too long to fit under their profile pic. Seems like a good use.

Music players, including car radios and portable CD and MiniDisc players, did that around 25 years ago. It's sort-of a standard UI pattern for variable-length text in a fixed-size display.

It’s used all over the place on Indian government websites, old and new. Often by <marquee>, sometimes by JS, maybe sometimes by CSS.

I never figured out why the actual <marquee> tag has a low frame rate. Maybe it’s to make it more unpleasant so you won’t want to use it. Certainly I would use a CSS animation instead for the frame rate reason, if I was forced to put a marquee on a page.

They can be useful in a tabbed interface. Since the width of a tab is limited, and may not be large enough to fit in the text, scrolling the text in the active tab title may be better than hovering to show a tooltip (Though we should use the tooltip for the inactive tabs).

Yeah, to really emphasize an important message.

Perhaps better semantics?