One of the option is using the language packs
that we have. Another option is through MainMenu - DataBound event.If you want just to change the MainMenu tabs you can easily do this from Sitefinity/Admin/Admin.master.cs. There is an event MainMenu_DataBound where you can access all Tabs and change the default text.
IList<RadTab> tabsCollection = MainMenu.GetAllTabs();
(RadTab t intabsCollection)
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!