ed and red (link to ed)
Ed is a line-oriented text editor. It is used to create, display, modify and otherwise manipulate text files.
red is a restricted ed: it can only edit files in the current directory and cannot execute shell commands.
Ed-0.2 needs the following to be installed:
bash: sh
binutils: ar, as, ld
fileutils: chmod, cp, ln, mv, rm, touch
gcc: cc
grep: grep, egrep
make: make
sed: sed
textutils: cat, tr