GNU ed is an 8-bit clean, POSIX-compliant line editor. Extensions to and deviations from the POSIX are described in the file `POSIX'. For a description of the ed algorithm, see Kernighan and Plauger's book "Software Tools in Pascal," Addison-Wesley, 1981. Bugs reports/suggestions for GNU ed are welcomed and may be sent to bug-gnu-utils@prep.ai.mit.edu.