In Application Server, you can execute tag files created as per the JSP syntax provided in JSP 2.0 or later. When you execute a tag file, the following contents are implemented:

• Transforming the tag file into a java class
• Compiling the transformed java class file
• Loading and executing the compiled file in JavaVM

If you use a tag file, you can describe the tag extension (that was conventionally achieved by a custom tag library) with the JSP syntax alone.