XT may refer to any of the following:
1. When referring to a computer, XT is short for extended technology and is the name of the IBM 5160 computer introduced on March 8, 1983. The XT was the first IBM computer with a hard drive (10 MB or 20 MB), a 5 1/4" floppy drive, up to 640 KB of memory, an Intel 8088 processor, an eight-bit ISA slot, and a serial port.
2. When referring to any communication, XT is an abbreviation for crosstalk.