英语翻译Middleware sits in the middle between application soft

英语翻译
Middleware sits in the middle between application software that may be working on different operating systems.It is similar to the middle layer of a three-tier single system architecture,except that it is stretched across multiple systems or applications.
我翻译了一下,总觉得不准确,特备是sit和stretch这两个词,不知道怎么翻译更准确
求整句的翻译

译文：中介软件处于“中间状态”,即·它很可能处于正在执行各种操作系统的应用软件之间.除了能延伸而越过多重系统或多重应用程序之外,它很象一个三层单系统结构的中间层 .
sit 动词意思是“位于,坐落于”,stretch 意思是“伸展,延伸”,此处它们都是不及物动词.