Regarding Dojo vs. SproutCore, it all comes back at looking at what we’re doing… Bespin is not at all a “normal webapp”, in that we’re working with DOM nodes and HTML interface elements, but it’s not in the context of a “page” sort of thing at all. Many things that matter a great deal to people putting together Ajax-enhanced websites matter not at all to us.

We weren’t really using much of Dojo: we used the module system and the basic DOM stuff (all just dojo base functionality). For the Reboot, we decided that we wanted to use CommonJS modules, with an ultimate goal of having plugins that offer both client-side and server-side functionality. And, the DOM stuff frankly doesn’t matter a whole lot. Dojo does just great there…

What we really wanted was a consistent, performant GUI toolkit that would take away a lot of bookkeeping work and let us focus on the functionality. More than one of us working on Bespin has a high opinion of certain Cocoa features at doing just that. SproutCore gives us those sorts of features in a well-constructed GUI toolkit.

So, starting from the notion of wanting to create the entire UI via JavaScript code, I prefer the way SproutCore lets us manage the UI to the way that Dijit does it. (Bindings and things of that nature do a great job at eliminating code for connecting up the various bits of UI.)