The GNU tool-set merged all three into grep, and kept the fgrep and egrep names for backwards compatibility. This is described in the man page in this manner:
> In addition, two variant programs egrep and fgrep are available. egrep is the same as grep -E. fgrep is the same as grep -F. Direct invocation as either egrep or fgrep is deprecated, but is provided to allow historical applications that rely on them to run unmodified.
That sure sounds like GNU. Instead of building tiny tools that each do one things, just make one big tool that can do a bunch of things depending on which of a hundred flags you use. Not to shit on GNU; I use GNU/Linux on all my own computers. But I notice that a lot of GNU software suffers from severe feature creep.
> In addition, two variant programs egrep and fgrep are available. egrep is the same as grep -E. fgrep is the same as grep -F. Direct invocation as either egrep or fgrep is deprecated, but is provided to allow historical applications that rely on them to run unmodified.