Nowadays people have to deal with an increasing amount of information contained in electronic documents available from numerous heterogeneous, widely distributed sources. Keeping up to date with recently published material relevant to a particular topic has become a challenge in itself. The Yaka system aims at facilitating this task by providing notification and delivery services. Yaka relies on a flexible definition of subjects through intelligent wrapping of existing information sources. Users can subscribe to these subjects in order to be notified whenever new relevant documents are published. Yaka augments document notification with document meta-information obtained through a set of integrated linguistic services. From the notification message users can directly request the document content. Yaka then delivers this content, automatically transformed into the appropriate format, through a variety of delivery media. In this article, we describe the Yaka functionality, its architect...