you potentially confuse some concepts / frameworks here. Spring Surf is basically a view definition and composition framework on the server side while Aikau is more like a development model of how to define new pages / components (based on Surf) in an easier and more adaptable manner. Aikau <b>cannot</b> replace Spring Surf nor can it be used without Surf. Please take a look at <a href="http://blogs.alfresco.com/wp/developer/2014/02/26/introducing-aikau/">Introducing Aikau</a>. Specifically it says that "Aikau refers to a method of creating new Surf Pages or Components comprised of small atomic widgets" and "Aikau leverages the existing Surf extensibility capabilities […]".
I have found a good documentation written by ohej:
"YUI, Dojo and AMD
Up until now, Share has been built on top of the YUI2 framework, and almost all of the current features in Share still use YUI2.
Share will eventually move away from YUI2 as it is not being developed anymore, and since there is no clear upgrade path from YUI2 to YUI3, Alfresco had to make a decision and chose to go with Dojo's AMD Module system.
<b>The Aikau framework relies on Dojo's AMD Module system to provide features for loading and extending widgets.</b>
"This does not mean that Alfresco is switching away from YUI and forcing users into Dojo.
Most of Share's future core modules will be based on Dojo, but this does not mean developers needs to learn and use Dojo for everything. However a bit of AMD knowledge will be needed, which is what defines widget and their dependencies. That's it. Once AMD is in place, it's up to the developers to load up another framework or use vanilla Javascript."
