Is it possible to add translation to smiley alt and title in CKEditor?
Never tried but I'm pretty sure that's possible.

If you use the ckeditor module, you can alter JS settings through PHP with hook_ckeditor_settings_alter.

Knowing that, it becomes pretty easy to wrap all strings with the t() function:

function yourmodule_ckeditor_settings_alter(&amp;$settings, $conf) {
  foreach ($settings['smiley_descriptions'] as $key =&gt; $smiley) {
    $settings['smiley_descriptions'][$key] = t($settings['smiley_descriptions'][$key]);
  }
}


If you use the wysiwyg_ckeditor module, you can use hook_wysiwyg_plugin. That's pretty much the same thing, you can find a pretty good example on how to use this hook here.

Again, the code hasn't been tested, but it should be a good starting point ;).