| ErrorData | Contains information about an error, for error pages. | 
| JspContext | 
 JspContextserves as the base class for the PageContext class and abstracts all information that is not
 specific to servlets. | 
| JspEngineInfo | The JspEngineInfo is an abstract class that provides information on the current JSP engine. | 
| JspFactory | 
 The JspFactory is an abstract class that defines a number of factory methods available to a JSP page at runtime for
 the purposes of creating instances of various interfaces and classes used to support the JSP implementation. | 
| JspWriter | 
 The actions and template data in a JSP page is written using the JspWriter object that is referenced by the implicit
 variable out which is initialized automatically using methods in the PageContext object. | 
| PageContext | 
 PageContext extends JspContext to provide useful context information for when JSP technology is used in a Servlet
 environment. |