Is ZoneMinder still being actively developed?

[tech_junkie]

Ha, silly me, why didn't I think of an internal web page? That's great, thanks! (I have a variety of cameras, a Hikvision, some Reolinks, some Cobra's (from a cheap Harbor Freight system, and others.)

So you are trying to consolidate viewing into one page, correct?
a lot of them have send alerts via email so that theoretically can be used and have it forward into your openHAB (which looks like a raspberry pi 4)
In your custom web page, you would use the <object> html tag for each camera.
you don't have to do any fancy php login (unless you want to) but if you do remember to sanitize your $_POST like: $user = htmlspecialchars($_POST['user'], ENT_QUOTES, 'UTF-8')
Just make sure you write the HTML page correctly and also declare the character set (UTF-8) with the meta tag.