off the trolley

adj. Describes the behavior of a program that malfunctions and goes
catatonic, but doesn't actually crash or abort. See glitch , bug , deep
space , wedged. This term is much older than computing, and is (uncommon)
slang elsewhere. A trolley is the small wheel that trolls, or runs against,
the heavy wire that carries the current to run a streetcar. It's at the end
of the long pole (the trolley pole) that reaches from the roof of the
streetcar to the overhead line. When the trolley stops making contact with
the wire (from passing through a switch, going over bumpy track, or
whatever), the streetcar comes to a halt, (usually) without crashing. The
streetcar is then said to be off the trolley, or off the wire. Later on,
trolley came to mean the streetcar itself. Since streetcars became common in
the 1890s, the term is more than 100 years old. Nowadays, trolleys are only
seen on historic streetcars, since modern streetcars use pantographs to
contact the wire.

