Linux is a free Unix-type operating system kernel originally created by Linus Torvalds with the assistance of developers around the world.
GNU GNU (pronounced /gnu/) is a computer operating system composed entirely of free_software. Its name is a recursive acronym for GNU's Not Unix.
vi vi is a free_software screen-oriented text editor computer program written by Bill Joy in 1976 for an early BSD release.
ncurses Ncurses is a programming library providing an API, allowing the programmer to write text user interfaces in a terminal-independent manner.
GCC The GNU Compiler Collection which includes front ends for C, C++, Objective-C, Fortran, Java, and Ada, as well as libraries for these languages.