计算机技术的迅速发展,对新一代的软件开发提出了新的需求。在日益复杂的分布异构环境中,通常存在多种硬件系统平台(如PC,工作站,小型机等),在这些硬件平台上又存在各种各样的系统软件(如不同的操作系统、数据库、语言编译器等),以及多种风格各异的用户界面,这些硬件系统平台还 The rapid development of computer technology has put forward new demands for the new generation of software development. In an increasingly complex distributed heterogeneous environment, there generally exist a variety of hardware system platforms (such as PCs, workstations, minicomputers, etc.) on which various system software (such as different operating systems and databases , Language compiler, etc.), and a variety of different styles of user interface, these hardware platform also