to change one XML format into another. But there are also transformers that take other forms of data (SQL commands for example). Serializers A serializer turns an XML event stream into a sequence of bytes (such as HTML) that can be returned to the client. Some serializers allow you to send the data in many different formats including HTML, XHTML, PDF, RTF, SVG, WML and plain text, for example. Selectors Selectors offer the same capabilities as a switch statement. They are able to select particular elements of a request and choose the correct pipeline part to use. Views Views are mainly used for testing. A view is an exit point in a pipeline. You can put out the XML-Stream which is produced till this point. So you can see if the application is working right. Readers Publish content without parsing it (no XML processing). Used for images and such. Actions Actions are Java classes that execute some business logic or manage new content production. The Pipeline A pipeline is used to specify how the different Cocoon components interact with a given request to produce a response. A typical pipeline consists of a generator, followed by zero or more transformers, and finally a serializer. See also Reactor pattern - the design pattern that Cocoon is based on. XProc - a W3C Standard for modelising of XML pipeline. References External links The Apache Cocoon Project Cocoon Web frameworks Java platform software