I'd say the most used are Bash, GCC, glibc, Make, GRUB, Grep, Gnome, Emacs, Gettext, GIMP, GTK, Gzip, Less, Screen, Sed, Tar, and Wget. But that's just a small

I'd say the most used are Bash, GCC, glibc, Make, GRUB, Grep, Gnome, Emacs, Gettext, GIMP, GTK, Gzip, Less, Screen, Sed, Tar, and Wget. But that's just a small sample, you can see the whole list here: https://www.gnu.org/manual/blurbs.html https://www.gnu.org/manual/blurbs.html