If you follow the link, there are two versions, the base version Unity (free), and their top of the line Unity Pro ($1500). And several (not free) addons for iOS and Android.

Will this save Unity? Unity’s initial announcement sparked widespread backlash from developers. Unity is widely used for free-to-play games, where a download fee would be particularly burdensome.

Unity Technologies has added the ability to develop for Android and iOS games for free using its platform.

UPDATE: David Helgason has detailed the thinking behind the decision to remove the license fee for the basic version of Unity on Android and iOS in a video at the bottom of the story. Unity CEO David ...

As the world’s leading platform for creating and growing games, Unity 6 is the most stable version of Unity, offering extended support and dedicated product and engineering resources post-launch.