by 1941, U.S. Marines slang, considered from boot (n.) as slang for "recruit," which supposedly dates through the Spanish-American War and it is a synecdoche from boots, leggings worn by U.S. sailors.
camp for training military recruits
computer software utility that has been first announced April 5, 2006 and very first included with Mac OS X v10.5 aka Snow Leopard. Training allows Apple computer system users to put in and operate Microsoft Windows XP, Vista, and 7 to their computers without dropping Mac OS.
Boot Camp [Morton Rhue]