In SharePoint 2010 we use three types of Client Object model extenstions. To get all items using .Net managed client Object model see -
.Net managed client Object model -

To get all items using ECMASCRIPT\Javascript object model see -
Using ECMAScript

In this post however, we will see an example of retrieving list items using Silverlight Client object model in SharePoint 2010.

using SP = Microsoft.SharePoint.Client;

namespace SPSilverlight
{
public partial class MainPage : UserControl
{
IEnumerable < SP.List > listItems = null;
public MainPage()
{
InitializeComponent();
}
private void getItemsSucceeded(object sender,
Microsoft.SharePoint.Client.ClientRequestSucceededEventArgs e)
{
Dispatcher.BeginInvoke(() = >
{
listBox1.ItemsSource = listItems;
listBox1.DisplayMemberPath = "Title";
});
}

private void getItemsRequestFailed(object sender,
Microsoft.SharePoint.Client.ClientRequestFailedEventArgs e)
{
Dispatcher.BeginInvoke(() = >
{
MessageBox.Show("Error: " + e.ErrorCode + " " + e.ErrorDetails + "
" + e.Message + " " + e.StackTrace.ToString());
});
}
private void button1_Click(object sender, RoutedEventArgs e)
{
ClientContext context = null;
if (App.Current.IsRunningOutOfBrowser)
{
context = new ClientContext(
"http://SP2010Site");
}
else
{
context = ClientContext.Current;
}
var query = from listCollection
in context.Web.Lists
where listCollection.Title != null
select listCollection;
listItems = context.LoadQuery(query);
ClientRequestSucceededEventHandler success = new
ClientRequestSucceededEventHandler(getItemsSucceeded);
ClientRequestFailedEventHandler failure = new
ClientRequestFailedEventHandler(getItemsRequestFailed);
context.ExecuteQueryAsync(success, failure);
}
}
}