Video streaming software with PTZ control?

I’m occasionally videoing some speeches.
At an event last week there was another guy who did the same thing and he had some fascinating equipment:
He had two tiny ptz cameras (pan-tilt-zoom). On his mac he had a video mixer where he could control the two cameras, and mix them together, live. His mixer had preset positions for the cameras, so that with a click on his screen he could make the cameras rotate and zoom into preset areas.
Does anyone know of a software for linux with similar functionality?

Second, what would be the proper search term to find cameras to use for this purpose? When I search for PTZ I find surveillance cameras. They are huge compared to what this guy had. His cameras, including the 2-axis motorized foot, were smaller than a gopro!

Mini PTZ Conference cam - sx.nix.dk

fixed the link - somehow I broke it

That link did not work..

The closest I’ve found in regards to camera is the Emeet Pixy

This thing, however seems to require a software not available to linux, and it’s using USB connection, which makes it complicated to have cameras positioned different places in a room - they are restricted by the length of a usb cable.

Looks like there is a PTZ control plugin to OBS (Open broadcast studio).
What it requires from the cameras is still a mystery

I got information which software that other guy was using:
Wirecast Pro