The Lite version of Wise Feline for Unity is now free on the assetstore. You can use it to release games and it is a feature ritch, fully functional Utility AI package with a visual debugger and visual designer. The full source code is available and you can use it to make great AI for your games.

There are a few advanced Utility AI features which are only available in Ultimate and Ultimate gives you influence maps, smart objects and other features but the Lite version is a very powerful package in its own right.