Hey, glad you like SACK, and yes: one advantage of it is that it is small, but as discussed here that is sometimes not an issue. It certainly isn’t an issue in really complex applications, because the overall code impact is probably small. However, as mentioned above, really large libraries can slow a browser down.

The main reason I wrote SACK however was because I wanted something that allowed me (and others) to use AJAX quickly, simpley, and without a lot of code that wasn’t needed for simple communication. Basically.. simplicity.

As said – it’s not quite the same as something like prototype (or Dojo!), but for many people that want to create AJAX apps it is nice, neat, and simple enough to satisfy their needs.