What is standard module in GWT?

Standard Modules GWT 1.5

Module	Logical Name	Module  Definition	Contents
User	com.google.gwt.user.User	User.gwt.xml	Core GWT functionality
HTTP	com.google.gwt.http.HTTP	HTTP.gwt.xml	Low-level HTTP communications library
JSON	com.google.gwt.json.JSON	JSON.gwt.xml	JSON creation and parsing
JUnit	com.google.gwt.junit.JUnit	JUnit.gwt.xml	JUnit testing framework integration
XML	com.google.gwt.xml.XML	XML.gwt.xml	XML document creation and parsing

Generally, you want to inherit at least the User module. The User module contains all the core GWT functionality, including the EntryPoint class. The User module also contains reusable UI components (widgets and panels) and support for the History feature, Internationalization, DOM programming, and more.


User.gwt.xml
<module>
   <inherits name="com.google.gwt.animation.Animation"/>
   <inherits name="com.google.gwt.canvas.Canvas"/>
   <inherits name="com.google.gwt.core.Core"/>
   <inherits name="com.google.gwt.debug.DebugBase"/>
   <inherits name='com.google.gwt.dom.builder.DomBuilder'/>
   <inherits name="com.google.gwt.editor.Editor" />
   <inherits name="com.google.gwt.event.Event"/>
   <inherits name="com.google.gwt.geolocation.Geolocation" />
   <inherits name="com.google.gwt.i18n.I18N"/>
   <inherits name="com.google.gwt.layout.Layout"/>
   <inherits name="com.google.gwt.media.Media"/>
   <inherits name="com.google.gwt.resources.Resources"/>
   <inherits name="com.google.gwt.safecss.SafeCss" />
   <inherits name="com.google.gwt.safehtml.SafeHtml" />
   <inherits name="com.google.gwt.storage.Storage" />
   <inherits name="com.google.gwt.text.Text"/>
   <inherits name="com.google.gwt.touch.Touch"/>
   <inherits name="com.google.gwt.uibinder.UiBinder"/>
   <inherits name="com.google.gwt.user.AsyncProxy"/>
   <inherits name="com.google.gwt.user.CaptionPanel" />
   <inherits name="com.google.gwt.user.cellview.CellView"/>
   <inherits name="com.google.gwt.user.ClippedImage"/>
   <inherits name="com.google.gwt.user.datepicker.DatePicker"/>
   <inherits name="com.google.gwt.user.DocumentMode"/>
   <inherits name="com.google.gwt.user.DocumentRoot" />
   <inherits name="com.google.gwt.user.DOM"/>
   <inherits name="com.google.gwt.user.FileUpload"/>
   <inherits name="com.google.gwt.user.Focus"/>
   <inherits name="com.google.gwt.user.Form"/>
   <inherits name="com.google.gwt.user.History"/>
   <inherits name="com.google.gwt.user.HTTPRequest"/>
   <inherits name="com.google.gwt.user.Hyperlink"/>
   <inherits name="com.google.gwt.user.ImageBundle"/> 
   <inherits name="com.google.gwt.user.Popup"/>
   <inherits name="com.google.gwt.user.RemoteService"/>
   <inherits name="com.google.gwt.user.ResizeLayoutPanel"/>
   <inherits name="com.google.gwt.user.RichText"/>
   <inherits name="com.google.gwt.user.Scroll"/>
   <inherits name="com.google.gwt.user.SplitPanel"/>
   <inherits name="com.google.gwt.user.TextBox"/>
   <inherits name="com.google.gwt.user.Tree"/>
   <inherits name="com.google.gwt.user.Window" />
   <inherits name="com.google.gwt.widget.Widget"/>

   <super-source path="translatable"/>
   <source path="client"/>
</module>