Excalibur
Geoffrey of Monmouth, in his "Historia Regum Britanniae" ("The History of the Kings of Britain", c. 1136), Latinised the name of Arthur's sword as "Caliburnus" (potentially influenced by the Medieval Latin spelling "calibs" of Classical Latin "chalybs", from Greek "chályps" ["χάλυψ"] "steel"). Most Celticists consider Geoffrey's "Caliburnus" to be derivative of a lost Old Welsh text in which "bwlch" (Old Welsh "bulc[h]") had not yet been lenited to "fwlch" (Middle Welsh "vwlch" or "uwlch"). In the late 15th/early 16th-century Middle Cornish play "Beunans Ke", Arthur's sword is called "Calesvol", which is etymologically an exact Middle Cornish cognate of the Welsh "Caledfwlch". It is unclear if the name was borrowed from the Welsh (if so, it must have been an early loan, for phonological reasons), or represents an early, pan-Brittonic traditional name for Arthur's sword.
Caliber (Radical Comics)
Caliber is a retelling of the Arthurian legend set in Pacific Northwest during the times of the frontier. Because of the changed setting, the characters have guns instead of swords. Instead of Caliber being a sword as tradition has it, it is also a gun, a six-shooter gun. The gun has the magical power of never missing when the shooter is attempting to attain a just cause, bringing a new aspect to the sword. As in the traditional story, young Arthur goes in hunt for Caliber, albeit in a different way because of the different time period. In addition, Arthur will not only have to retrieve the weapon; he will only be able to use it in a just way.