Aka. Sun 4/25.
An old Sun Sparc workstation, very similar to the SparcStation SLC. So similar in fact that the mainboards are interchangable.
An ELC usually comes configured with the following (in no particular order):
Makes a fairly nice
X-Terminal using
NetBSD, as long as you don't need
colour.
It should be noted that Linux shouldn't be attemped on anything based on the Sun4C architecture (like the ELC) as it's memory management code it quite broken when used on the Sun4 MMU, so stick to NetBSD/OpenBSD and you'll be very happy.