Velocity,FreeMarker

What is Velocity?
Velocity is Templet Language.Velocity can be used to replaced the JSP.

Why u are using Velocity?
Velocity is introduced as a replacement for the JSP.It is a simple template language and it is used as the form the document.
There is no java class in a velocity template.It is just an HTML document with some velocity place holders.
Velocity isolates java code from the webpages,making websites more maintainable.

Give me one example of Velocity?

Login.vm:

Hello $name
ur company:$comapny

FreeMarker:

What is FreeMarker?
FreeMarker is a "template engine"; a generic tool to generate text output (anything from HTML to autogenerated source code) based on templates. It's a Java package, a class library for Java programmers. It's not an application for end-users in itself, but something that programmers can embed into their products.
FreeMarker is designed to be practical for the generation of HTML Web pages, particularly by servlet-based applications following the MVC (Model View Controller) pattern. The idea behind using the MVC pattern for dynamic Web pages is that you separate the designers (HTML authors) from the programmers. Everybody works on what they are good at.
Designers can change the appearance of a page without programmers having to change or recompile code, because the application logic (Java programs) and page design (FreeMarker templates) are separated.
Templates do not become polluted with complex program fragments. This separation is useful even for projects where the programmer and the HTML page author is the same person, since it helps to keep the application clear and easily maintainable.
Although FreeMarker has some programming capabilities, it is not a full-blown programming language like PHP. Instead, Java programs prepare the data to be displayed (like issue SQL queries), and FreeMarker just generates textual pages that display the prepared data using templates.
FreeMarker is not a Web application framework. It is suitable as a component in a Web application framework, but the FreeMarker engine itself knows nothing about HTTP or servlets. It simply generates text. As such, it is perfectly usable in non-web application environments as well.
Note, however, that we provide out-of-the-box solutions for using FreeMarker as the view component of Model 2 frameworks (e.g. Struts), which also let you use JSP taglibs in the templates.