Learn how you can use the Apache XML Project's Cocoon (xml.apache.org/cocoon/) to serve complex content to a wide array of devices. In our sample Web site, Cocoon ties everything together: content is created and managed with XML, retrieved with Cocoon's SQL, XSP, and DSP processors, and formatted with the Apache XSL processor, Xalan. Our demo includes a one-to-one marketing sample in which Cocoon finds the content that appeals to a given user, then transforms the content based on that user's current device. Best of all, Cocoon's intelligent caching facility delivers this custom content with good performance.