Without an exception : if one knows Maven, that one will ask us the question : "Why don't you use Maven for this ?". Well, the basic answer is simple : "The purpose of Karma is different."
The following list describes the main differences between the two. We're not trying to prove that Karma is better here. We're just pointing out the differences for you so you make your own choice. We value your comments.
There's a lot more to be said about this. Coming soon.
Ok, since we convinced you that Karma is indeed different from Maven and Ant, one could ask the question : "Why don't you integrate with them?". In fact, that's what Karma does. Without a doubt, Ant and Maven are great in what they do, and we don't intend to beat them in that. Karma uses Ant a great deal in the build and package proces. We've tried to integrate with Maven, but the integration level is - in our opinion - a bit meagre. We've been told that integration on the Java level will improve from Maven 2.0 onwards, so who knows what will happen in the near future with Karma, but for now, we stick to Ant.