The old trial keys included a Trial splash as well as the Wikitude logo on the screen and had a time validity of a few years. Starting with SDK 9, Trial Keys have a new format: no trial splash, only the Wikitude logo on the screen, and valid for 14 days. 

Both Keys are free, include access to the same features, and have the purpose of facilitating developer testing. They do not include the right to publish the app in the app stores or to use the license for direct commercial profit.