No subject

or suite and not per command and also not many behind the scenes 
libraries listed here):

- Linux kernel (some Linux systems don't run glibc)
- glibc (runs on some platforms not Linux based)
(Linux abd glibc probably tied for first)

- coreutils

- bash

- vixie cron

- GNU grep

- X.org (even though splitting between XFree86, I think is still popular)

- openssh client (It may be installed more places, but I am assuming more 
people use X.org that openssh.)

- ncurses

- perl

- GNU awk (even if others use nawk and mawk)

- cups

- curl

- BIND utilities (not named)

- sysklogd

- less

Some I didn't include above:

gcc -- widely installed, but not used by everyone

man -- few different implementations

vim -- I know widely installed, but not every one uses it. (My wife has 
never used vi or vim even though she has used open source Unix for 6+ 
years.)

gzip

bzip2

flex

tar -- many implementations

groff

tnftp


What do you think? Do you know of any lists?

  Jeremy C. Reed