Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It represented the largest overhaul of the Mac OS since the release of System 7, some six years previously. It puts more emphasis on color than previous operating systems. Released over a series of updates, Mac OS 8 was an effort to integrate many of the technologies developed for Apple's overly-ambitious operating system known as Copland. Mac OS 8 helped modernize the Mac OS while Apple developed its next generation operating system, OS X. Mac OS 8 is one of Apple's most successful software releases, selling over 1.2 million copies in the first two weeks. Coming as it did at a difficult time in Apple's history, many pirate groups refused to traffic in the new operating system, encouraging people to buy it instead. Mac OS 8.0 brought about the most significant changes in the line-up, including the introduction of the Platinum interface and a native PowerPC multi-threaded Finder. Mac OS 8.1 introduced a new, more efficient file system known as HFS Plus. Mac OS 8.5 was the first version of the Mac OS to require a PowerPC processor. It featured PowerPC native versions of QuickDraw and AppleScript, along with the Sherlock search utility. Its successor, Mac OS 9, was released on October 23, 1999.