Les Cahiers du Cinema was the publication on film criticism from the 1950s-1970s. Literally, "Notebooks of the Cinema," the magazine was founded in 1951 by Andre Bazin, one of the great pillars of early film theory. It quickly collected a set of writers and directors inflicted upon and/or worshipped by film students ever since; they include Eric Rohmer, Francois Truffaut, Claude Chabrol, and Jean-Luc Godard.

The Cahiers are the main reason why art film snobs tend to sound like they're speaking French half the time. Many of their terms like film noir, auteur, and nouvelle vague (or New Wave, a cinematic movement they pretty much created) leaked off the journal's pages and at least nominally into the English language. (hey, at least they come up in the ol' Merriam-Webster) Not to mention their leakage into the heads of the next generation of Hollywood filmmakers!

Although it's not been accused of turning the film world upside down in recent years, the magazine is still around, on sale right next to Premiere in French tabacs everywhere.

Source: history classnotes, plus a little fact-checking at http://www.hoveyda.org/cahiers.html

The Cahiers are also the source of the urban legend that Jerry Lewis is a great star in France, and taken very seriously...grist for the mill of a thousand "The French think they're so smart, eh?" jokes since.
Apparently, in their early days, they were on a "don't write this (American) film off as mere fluff" kick, (they did a similar job on "Bells are Ringing", a not-shabby, but not altogether earthshattering musical, as well), and Lewis's films came up as examples of American comedy in the tradition of Charlie Chaplin in one (and only one) article, a detail overlooked by most retellers. Since most of what people knew about French film was what was in the Cahiers, this easily passed into common currency.

The Cahiers also passed a time talking mostly about non-film subjects (in the late 60's) but no one seems to remember that either. Next WU, maybe I'll discuss JFK's real interest in James Bond...