Update (Dec 2011): Hello web searchers! If you're looking for more information about GeoExplorer, you can download the source code at our GitHub repository, see a live demo, or download it as part of the OpenGeo Suite. Questions about using GeoExplorer should be directed to our OpenGeo Suite Community Forum. Thanks!
The developers at OpenGeo have been working with others toward an initial release of the GeoExt toolkit. GeoExt brings together the spatial capabilities of OpenLayers with the user interface power of ExtJS. To demonstrate the types of applications that can be built with GeoExt, we're putting out a preview release of GeoExplorer.
The goal of GeoExplorer is to make it easy for anyone to assemble a browser based mapping application with functionality traditionally found in the desktop GIS world. The GeoExplorer preview release includes basic layer browsing capabilities and can be placed in front of any compliant WMS.
After the initial release of GeoExt, we'll be rolling out a more feature filled version of GeoExplorer. Upcoming releases will include a wizard for configuring a GeoExplorer application with your own layers and publishing options for embedding the app in any web page.
Update: The preview release has been retired but there is a GeoExplorer demo available as part of our online Suite demo. GeoExplorer is now one of the applications bundled with the OpenGeo Suite. You can still download and build GeoExplorer to run without the Suite. Find the source code link on the Community Edition download page.