The rapid expansion of the Internet accompanies a serious side effect. Since there are too many information providers, it is very difficult to obtain the contents best fitting to customers' needs. Web Syndication Services (WSS) are emerging as solutions to the information flooding problem. However, even with its practical importance, WSS has not been much studied yet. In this paper, we propose the Content Aggregation Middleware (CAM). It provides a WSS with a content gathering substratum effective in gathering and processing data from many different source sites. Using the CAM, WSS provider can build up a new service without involving the details of complicated content aggregation procedures, and thus concentrate on developing the service logic. We describe the design, implementation, and performance of the CAM.