Pagelets Technology project allows developers to embed Java scripting elements inside of text documents in order to generate dynamic text-based output.
The idea and functionality behind Pagelets is very similar to Java Server Pages with one huge difference - Pagelets are not tied to the HTTP protocol. That difference opens up a plethora of new possibilities and uses for the technology.
For example, Pagelets can be used to dynamically render the content of email messages, or as a simple source code generator, or to render dynamic content in any other environment - whether that environment is tied to the HTTP protocol or not. Basically, Pagelets are - JSP without HTTP.