Revision with unchanged content. In order to obtain an acceptable quality of filtering services in real time conditions a trade-off between relevance of results and response time has to be addressed while searching for needed information in numerous distributed repositories. Unfortunately, ignoring a necessity to address information retrieval in distributed and resource-aware manner is usually a serious drawback for many existing search engines that try to survive an ongoing information explosion. The essence of a proposed distributed approach for information retrieval is in comprehensive coordination and cooperation mechanisms which both take care of current availability of resources and try to improve themselves during runtime. Additionally, they are able to guarantee delivery of results by combining multiple filtering strategies with very different capabilities and by using inbuilt self-healing for recovery after failures. As the realization of the proposed mechanisms is described in details and experimentally proven, this book is mainly addressed to professionals in distributed information retrieval and advanced search engine technologies. It is also directed towards researches in filtering strategies and agent technologies.