Is XP an upgraded form of Waterfall and Iterative models?

Hello:

It depends on what you would like to call as an upgraded version. XP and the super set - Agile is much more than just iterative and incremental. You can check out this article found out by a Google search for more: http://www.agilecollab.com/iterative-and-incremental-is-not-equal-to-agile-key-aspects-of-agile

Thanks