Linux – Why did wireless tools version 30 become a permanent beta

vi is inspired by ex, ex is inspired by ed, ed is inspired by qed

QED was hacked together by Ken Thompson way back in the late 1960's for MIT's "Compatible Time-Sharing System" (a previous version for the Berkeley Timesharing System was created by Butler Lampson, L. Peter Deutsch, and Dana Angluin) — in short Thompson added regex in qed (he did a lot more than that, but it's outside the scope of this answer. -- Bell Labs has more on the history of QED)

One command in qed was the "G" or "Global" command. It allowed you to operate on all lines in the file at once (the previous version of qed were character-oriented instead of line oriented.)

Grep is actually named for one of the uses of this command G/re/P (G global, re regular expression, P print) in qed this command was used like G/bash/P to print out all lines containing the word bash — this was later included in ed, then taken out of ed and made into a standalone function (according to Doug McIlroy, he asked Ken to do it for him & Ken left it on his desk the next morning)

From The Art of Unix Programming (emphasis added):

After the [1974] paper, research labs and universities all over the world clamored for the chance to try out Unix themselves. Under a 1958 consent decree in settlement of an antitrust case, AT&T (the parent organization of Bell Labs) had been forbidden from entering the computer business. Unix could not, therefore, be turned into a product; indeed, under the terms of the consent decree, Bell Labs was required to license its nontelephone technology to anyone who asked. Ken Thompson quietly began answering requests by shipping out tapes and disk packs — each, according to legend, with a note signed “love, ken”.

There is much more relevant information in that chapter; its title is "Origins and History of Unix, 1969-1995". Highly recommended reading (along with the rest of the book!) :)