le (text editor)

le has many block operations with stream and rectangular blocks, can
edit both unix and dos style files (LF/CRLF), binary clean, has hex
mode, can edit text with multi-byte character encoding, has full
undo/redo, can edit files and mmap-able devices in mmap shared mode
(only replace), has tunable syntax highlighting, tunable color scheme
(can use default colors), tunable key map.  It is slightly similar to
Norton Editor, but has more features.
