What is "com.google.gwt.core.client.JavaScriptException: (TypeError): $wnd.OpenLayers has no properties"?

This means that the OpenLayers javascript library is not loaded on your page. At present, OpenLayers is not included in the GWT-OpenLayers module, so you have to make sure to include OpenLayers in your project. GWT-OpenLayes is compatible with OpenLayers 2.4 and up, but using OpenLayers 2.7 is adviced. There are at least two ways in which OpenLayers can be included in your GWT project. * in the head tag of your application html * in the GWT module xml

Method 1 - Include OpenLayers in the head tag of your html:

  <script src="YOUR_PATH_HERE/OpenLayers.js" type="text/javascript"></script>

Method 2 - Include OpenLayers JavaScript in your GWT module xml:

 <script src="YOUR_PATH_HERE/OpenLayers.js"/>

See also "Automatic resource inclusion" in the GWT documentation on how to link javascript files via the GWT module xml.

How do I integrate GWT-OpenLayers in smartgwt?

Read this thread http://forums.smartclient.com/showthread.php?t=4368&highlight=openlayers