The purpose of the Autonomous Web Services (AWS) is to enable business transaction exchange in the Internet between systems having different business process models, by dynamically harmonizing them when the systems encounter. Based on the principles and the basic methods proposed in the previous researches such as [3], we succeeded in development of the experimental implementation of the AWS middleware. The AWS middleware consists of three software layers - the dynamic model harmonization layer, the application framework layer, and the messaging layer. This paper mentions the development principles, operation concepts, proposed specifications, detailed algorithms and test results of the AWS middleware that we developed. This success of implementation demonstrates the AWS's theoretical properness and its availability to real world applications, as well as the applicability of the improved model harmonization algorithm proposed in this paper.