Apple has announced that it has completed work on its Mac OS X and released it to manufacturing for production. Mac OS X will ship on March 24 for a suggested retail price of £99, the company said in a statement. The release date is consistent with what Steve Jobs, Apple's chief executive officer, told the Mac faithful at the MacWorld conference and expo in San Francisco in early January. Mac OS X is built on an open-source, Unix-based foundation called Darwin and features memory protection, preemptive multi-tasking and symmetric multiprocessing when running on the dual processor Power Mac G4, according to Apple. Mac OS X features Apple's new Quartz 2D graphics engine, OpenGL for 3D graphics and gaming and QuickTime for streaming audio and video. Mac OS X also includes a new user interface called Aqua, which provides ease of use with greater functionality, Apple said. The user interface provides a feature called Dock, which organizes applications, documents and document windows. Apple will make Mac OS X available through The Apple Store (http://www.apple.com/ukstore) and through Apple Authorized Resellers. Mac OS X will be preinstalled as the standard operating system on Macintosh computers by June, according to the company. The operating system requires a minimum of 128MB of memory and is designed to run on iMac, iBook, Power Macintosh G3, Power Mac G4, Power Mac G4 Cube and PowerBook introduced after September 1998, the company said.