A somewhat belated reply to this thread, as I read the list irregularly...
DECserver series: Some models are LAT only (such as 100, 200, 90), some
also talk TCP/IP. Note there is also a TCP capable version of the 90
called the 90TL. I believe there's an open source LAT daemon now. The
90 is a compact 8 port module that plugs into the DEChub-90 or DEChub-1.
Some of these will need a MOP server to boot. Any of these should be OK
to attach terminals to. IIRC, I wasn't able to associate DECserver-100
ports with services for attaching it to a console port ("reverse LAT"),
only some models support that. DS550 is a big box with a PDP inside,
90 and 900 are little, 100/200/300 are in between.
Lantronix: ETS series terminal servers are compact boxes with varying
numbers of ports, with a DECserver-like interface. They can be used as
terminal servers as well as console servers. EPS series devices are
intended as print servers -- IIRC you can use as console servers, but
not as terminal servers, because the commands for outgoing connections
are gone. There's also the LRS series, which were intended as small RAS
boxes, but will also be OK as console or terminal servers -- but the
LRS2 hardware seems to have problems. The LRS1 is OK. They also have a
few other product lines such as MPS. Many of their products talk both
TCP and LAT, some of them are TCP-only unless you purchase a LAT license.
Some of them can be used as TCP/LAT gateways.
Shiva LanRover: Intended as a RAS, can also be used as a console server.
1U rackmount box with up to 8 ports. Probably not useful as a terminal
server, unless you have a machine that can talk the Shiva Hose protocol
and take over the ports. (It's been a while but I don't believe it wanted
to give a login prompt to an attached device that doesn't act like a
modem.) They also made an OEM version for IBM. TCP.
Xylogics Annex: A few different products, usable as console or terminal
servers. Annex 3 squeezes dozens of ports onto one box, with Centronics
connectors.
Livingston Portmaster: This series was popular with ISPs as a RAS, can
also be used as a terminal or console server IIRC. TCP.
Bridge Communications CS/100, 3Com CS/2100: Not sure what exactly these
will do, but without the boot floppy or TFTP image, they won't do much
useful! The software was available in several versions including one
that only talked OSI. A dozen or so ports.
Xyplex, Emulex, others: Various DECserver workalikes.
LAN Access LANAserver: Dunno much about this except it was available
with 4 and maybe 8 ports, it's 1U and it has an LCD on the front. Company
was sold to Digi in '95, they sold the product to NNTI, NNTI went out of
business. I think Digi might have also had their own product.
Cyclades: They make some sort of nifty little box with L*n*x inside, I
think it's intended as a console server.
Cisco: They made a box with a bunch of serial ports, I think it was
intended as a RAS but could be used as a console server and maybe a
terminal server.
Hmm, I know I'm forgetting something here...
-- Adam