This is a free but official plugin for Joomla 3.x and should be working on 2.5 as well (tested only on 3).
More info in Joomla directory: https://extensions.joomla.org/extensions/extension/style-a-design/typography/3d-text-shadow/
The official Joomla extensions directory: https://extensions.joomla.org/profile/profile/details/325855/
