(1) (Enhanced Definition) See EDTV.

(2) (ed) (EDitor) An early Unix line editor (text editor) that contained functionality later incorporated into vi. The sed editor (Stream EDitor) supersedes ed and, using ed commands, processes the entire text file instead of one line at a time. See sed.

(3) (ED) (Extra High Density) Refers to earlier 2.88MB floppy disks from IBM. Although IBM doubled the floppy's capacity, it was not enough to become a widely used standard. See floppy disk.