Thymeleaf

Thymeleaf is a Java XML/XHTML/HTML5 template engine that can work both in web (servlet-based) and non-web environments. It is better suited for serving XHTML/HTML5 at the view layer of MVC-based web applications, but it can process any XML file even in offline environments. It provides full Spring Framework integration.

In web applications Thymeleaf aims to be a complete substitute for JavaServer Pages (JSP), and implements the concept of Natural Templates: template files that can be directly opened in browsers and that still display correctly as web pages.

Thymeleaf is open-source software, licensed under the Apache License 2.0.

Features
From the project's website:
 * Java template engine for XML, XHTML and HTML5.
 * Works both in web and non-web (offline) environments. No hard dependency on the Servlet API.
 * Based on modular feature sets called dialects.
 * Dialect features (e.g.: evaluation, iteration, etc.) are applied by linking them to template's tags and/or attributes.
 * Two dialects available out-of-the-box: Standard and SpringStandard (for Spring MVC apps, same syntax as Standard).
 * Developers can extend and create custom dialects.
 * Several template modes:
 * XML: validating against a DTD or not.
 * XHTML 1.0 and 1.1: validating against standard DTDs or not.
 * HTML5: both XML-formed code and legacy-based HTML5. Legacy non-XML code will be automatically cleaned and converted to XML form.
 * Full (and extensible) internationalization support.
 * Configurable, high performance parsed template cache that reduces input/output to the minimum.
 * Automatic DOCTYPE translations –from template DTD to result DTD– for (optional) validation of both template and result code.
 * Extremely extensible: can be used as a template engine framework if needed.
 * Complete documentation including several example applications.

Thymeleaf example
The following example produces an HTML5 table with rows for each item of a List variable called allProducts.

This piece of code includes:
 * Internationalization expressions:  #{ ... } rh 
 * Variable/model-attribute evaluation expressions:  ${ ... } 
 * Utility functions:  #numbers.formatDecimal( ... ) 

Also, this fragment of (X)HTML code can be perfectly displayed by a browser as a prototype, without being processed at all: it is a natural template.