I know that some projectors/TVs have a PIP (Picture in Picture) function but I have only seen it with at most two different input sources being simultaneously displayed on the same monitor. I think EPSON has a multiview technology in some of their projectors but I was wondering if there is an adapter similar to a KVM Switch that could perform this function but just do it simultaneously? Thanks for all the help!
I like LPChip's answer better as it's much cheaper (much much cheaper).
If you wanted a hardware solution this looks to do what you want, but it's going to set you back a few grand.
I've found Microsoft's Remote Desktop Connection Manager to be remarkably useful when managing multiple RDP sessions.
It's free, and you can organise your servers into a tree of sub-groupings, remember logon credentials for each server or group, or inherit from the parent group (or just prompt you for them), and the thumbnail images of each server are resizable and live, meaning you can actually click into them without having to expand each one. This makes doing batch installs of software really easy, and if you make them big enough you can use it for what you need (I run with the thumbnails scaled so big that only two fit in the width of my monitor, it works well for actually using the machines at that scale).
I see you said that at least one of the machines is running Linux, but that shouldn't be a problem thanks to XRDP.