Raritan is the name you hit the moment you stop looking at desk switches and start looking at how data centres are actually run. The Dominion KX line has been the default answer to "how do I reach 32 servers that are nowhere near me" for most of two decades.
The company behind it started in a house.
A couple selling PC parts from home
Raritan was founded in 1985 by Ching-I Hsu and his wife, reselling PC components from their home before moving into building PCs themselves. It is based in Somerset, New Jersey, and now has a commercial presence in over 76 countries.
The pivotal moment, as the company's own account has it and as reference sources repeat, is that Hsu developed the first KVM switch: a way to control several PCs from one keyboard, monitor and mouse. Whether any single product can really claim to be first in a category that several companies arrived at around the same time is the sort of thing that is hard to settle. What is not in dispute is that Raritan was there at the beginning and that the product is what turned a local PC business into an international one.
Two later moves defined the modern company. It entered the intelligent power business in 2007, and its Data Center Infrastructure Management software business began in 2008. Those three legs, KVM, power and management software, are what made it an acquisition target.
The Legrand split
In June 2015, Legrand announced an agreement to buy Raritan's intelligent power and KVM businesses, and the deal completed on 28 September 2015.
The interesting part is what was carved out. The DCIM software business did not go to Legrand. It was spun off into a separate company, Sunbird Software, chaired by Hsu himself and positioned as a strategic partner rather than a subsidiary.
So the Raritan brand you buy hardware from today is a Legrand subsidiary, while the software side went its own way under its founder. If you are researching the company and find two entities with shared history telling slightly different stories, that split in 2015 is why.
What the hardware actually does
Raritan's catalog divides cleanly, and the division tells you who each product is for.
Enterprise KVM over IP. The Dominion KX III is the workhorse. It comes in a grid of configurations defined by two numbers: how many simultaneous users, and how many server ports. Our catalog carries that grid, from the single user 8 port up through two user 32 port and four user 32 port models, to the eight user 32 port and the four user 64 port DKX3-464.
That user count is the specification people get wrong. A 32 port switch with one user channel means one administrator at a time, no matter how many servers are attached.
The newer Dominion KX IV-101 goes the other way: a single server, but 4K capable, for when the one machine you need to reach remotely is doing something that needs real resolution.
Serial and mixed access. Plenty of data centre equipment still has a serial console and no video output at all. The Dominion SX 2 handles 4 to 48 serial ports, and the Dominion KSX II mixes KVM, serial and power control in one box for remote sites where you cannot send someone to press a button.
Secure desktop switches. A separate line entirely. The RSS4-104 and SS4-104-DUAL are certified to NIAP PP4.0, and the RSS series such as the RSS-104C4K adds smart card support. Same purpose as the secure ranges from Adder and Vertiv: keep two networks physically apart at one desk.
Out-of-band is the whole idea
The phrase that explains Raritan better than any product name is out-of-band access.
In-band management means reaching a server over the network, using the server's own operating system. It works right up until the moment you need it most. If the OS has hung, the network stack has fallen over, or you need to watch the machine POST and get into BIOS, in-band gives you nothing.
Out-of-band is a separate path to the machine that does not depend on the machine working. A KVM over IP switch gives you the screen, keyboard and mouse as though you were standing at the rack, even when the server is in a state where nothing else can reach it.
That is why these products survive in an era of cloud and remote management. Software management fails in exactly the situations where you most need access.
The same logic drives the competition. Adder applied it to broadcast galleries, Avocent applied it to secure government desks, and ATEN applied it to everything at once, but the underlying problem is identical.
Is any of this for you
Probably not, unless you run a rack.
For a desk, a Raritan Dominion is absurd, and our round-up of the best KVM switches is the right starting point instead. For a two machine setup at home, a KVM switch for a two PC battlestation is the relevant guide.
The exception is the home lab. If you have a small rack and you are tired of carrying a monitor to it, a used single user Dominion from the secondary market is a reasonable buy. These things are built to run for a decade and plenty of them come out of data centre refreshes long before they stop working. Check what firmware it is on and whether the Java based remote client has been replaced by HTML5 on that generation, because the older interfaces are genuinely unpleasant to use on a modern browser.
Where the information here came from
Founding, ownership and corporate history is from the public record as summarised on Wikipedia, including the 2015 Legrand acquisition and the Sunbird Software spin-off. Product configurations come from our own catalog entries, built from manufacturer documentation.
We have no commercial relationship with Raritan or Legrand.