NE is a text editor that was originally implemented in the early 1990s to run on a number of different operating systems. Nowadays it runs only in Unix-like environments. It can process files in three ways: as single-byte characters, as UTF-8 multibyte characters, or as binary bytes displayed and edited in hexadecimal. NE runs as an interactive screen editor when the terminal supports such usage, but it can also run as a line-by-line editor, interactively or driven by a script. Function keys and some others are fully configurable in interactive screen mode. You can read the NE manual on this GitHub site.