This tag handler accepts a "num" parameter and repeats the body of the tag "num" times. It's a simple example, but the implementation of such a tag in JSP 2.0 is substantially simpler than the equivalent JSP 1.2-style classic tag handler.
The body of the tag is encapsulated in a "JSP Fragment" and passed to the tag handler, which then executes it five times, inside a for loop. The tag handler passes in the current invocation in a scoped variable called count, which can be accessed using the EL.