Localizing an app using Telerik UI for Windows 8 HTML is no different than localizing a regular app.
If you need to localize a Telerik control, you will also need to know the names of the supported strings and
their purpose. You can find the preset .resjson files in your Telerik UI for Windows 8 HTML
installation directory, e.g.
'C:\Program Files (x86)\Telerik\UI for Windows 8 HTML Q3 2012\strings\en'
and copy them to the directories of all locales, for which you would like to prepare your app, e.g., de-De, fr-CA, etc.
The Telerik UI strings are isolated in a separate resource map for each control,
e.g. strings\en\raddatepicker.resjson for common use and easier maintenance.
Then you can translate each string in the file as you would normally
do for the rest of the string resources in your app.
The following controls have built-in strings and support localization: