关于移植的几个概念

adoption:The term adoption is used to refer to instances for which you add or change an implementation without changing the interface.
如操作系统从win98升级到win2000后，一些系统接口发生了改变，我们原来在win98下开发的程序要移植到
win2000下，就要对我们的应用程序进行修改，称之为adoption。 
upgrade:an upgrade implies changes in the underlying technologies or interfaces, which require substantial application changes.
如操作系统的升级，win98换为win2000，就是upgrade
porting:the term porting applies to applications rather than infrastructures.
仅指简单的代码移植
migration:The term enterprise migration refers to the process of migrating all layers of the E-stack, not only the application that supports business functionality.
与系统有关的一系列架构、程序等的移植。
概念理解了，就该上路了。