Apache JServSSI Project
   Describes the predecessor to JSP technology; includes syntax and distribution. [Open Source, BSD-like]
   http://archive.apache.org/dist/java/

FreeMarker
   Java template engine; a generic tool to generate text output (HTML, RTF, and source code) based on templates. Particularly practical for servlet-based Web applications following the MVC pattern. [Open-source, BSD-style]
   http://freemarker.org/

Tea
   A simple yet powerful template language. Tea is most commonly used for creating dynamic web pages in the TeaServlet. [Open Source, Apache-like]
   http://teatrove.sourceforge.net/tea.html

The Rich Mens Document Management System (rm -d ms)
   XML/XSL based document management system designed for running websites. Server side application logic is implemented by XSL stylesheets, which may call hard-coded components. [Open Source, GPL]
   http://rmdms.sourceforge.net/

WebMacro Servlet Framework
   A server-side scripting engine. It uses Java introspection to make any object in your servlet accessible in your scripted template. [Open Source, GPL/Commercial]
   http://www.webmacro.org/