Windows 8 introduced major changes to the operating system's platform and user interface intended to improve its user experience on tablets, where Windows was now competing with mobile operating systems, including Android and iOS. Windows 8 was made available for download via MSDN and TechNet and available as an upgrade to all Windows 7 users via Windows Update. The product was released to manufacturing on August 1, 2012, and generally to retail on October 26, 2012. Windows 8 is a major release of the Windows NT operating system developed by Microsoft.