public class Result
{
    public string CategoryName { get; set; }
    public string Description { get; set; }
}

<UserControl.Resources>
    <CollectionViewSource x:Key="resultsCollection"
                          Source="{Binding Results}">
        <CollectionViewSource.GroupDescriptions>
            <PropertyGroupDescription PropertyName="CategoryName" />
        </CollectionViewSource.GroupDescriptions>
    </CollectionViewSource>
</UserControl.Resources>

<TabControl ItemsSource="{Binding Source={StaticResource resultsCollection}}">
    <TabControl.GroupStyle>
        <GroupStyle>
             <GroupStyle.HeaderTemplate>
                 <DataTemplate>
                     <TextBlock Text="{Binding Name}" />
                 </DataTemplate>
             </GroupStyle.HeaderTemplate>
        </GroupStyle>
    </TabControl.GroupStyle>
</TabControl>