Video wall software or software for online viewing of video from IP cameras?

Question

CCTV

Good day!
There are various cameras at various sites (up to 40, but for now), recording is in progress - everything is OK!
If you are interested, then: in the linux + motion + ffmpeg (avconv) + zoneminder bundle, plus there is an object with an analogue, but giving streams from cameras in RTSP (Geovision)
But! There is one problem: the
management wants to see all the cameras online on their computer, and of course for free or for a small amount. You need software that will do it.
Software requirement: an unlimited number of cameras, support for JPEG, MJPEG, RTSP streams, displaying cameras in a similar form as video walls, if you can divide cameras into groups to display pictures from cameras in groups, then in general my joy will be immense. Nothing else is required from the software except for displaying images from cameras.