The Acme Corporation is a fictional corporation that exists in the Looney Tunes universe.
The company is never clearly defined, but apparently exists as some degree of monopoly which produces everything and anything imaginable (making the explanation "A Company that Makes Everything" a good guess), no matter how elaborate or extravagant. In Warner Bros. cartoons, Acme products were most commonly purchased (by mail) by Wile E. Coyote who ordered many weapons in his failed attempts to catch the Road Runner. There were also commonly seen in Bugs Bunny and Daffy Duck cartoons.
The Tiny Toons Adventures series expanded on the Acme universe, with the entire setting of the show taking place in a city known as "Acme Acres." The show's teenage protagonists attendeed Acme Looniversity.
The movie Who Framed Roger Rabbit attempted to explain Acme's inner workings in greater detail. The movie's plot centers around the murder of Marvin K. Acme, the multi-millionaire founder and CEO of Acme Incorporated.
In the movie Last Action Hero with Arnold Schwarzenegger, some bad guys throw ACME dynamite at the hero Jack Slater.
In most of the recently-produced Disney cartoons seen of House of Mouse, Disney has answered to Acme by making a similar company of their own, Ajax.