Hi, I have designed on paper new algorithms for to insert, delete and balance the countertree, in order to improve the speed. The actual version is around 10% - 15% slower than the GCC version of red-black trees. The new version is easy to understand, and I hope, offer better results. In the new version you have a catalog of operations with the nodes. The node operations have two parts, the pointers and the node color, and the augmented information. In the countertree the augmented information are the node counters. But if you design the process to do with your augmented information for all the operations of the catalog, you can create your augmented tree with the pointer and color operations, and your code for each operation. And you can have augmented trees with several concepts, like the position, and an accumulator of the value of the nodes. I hope begin to work with the new algorithms at Christmas. If you are interested, when I have something useful , I will comment and offer to you. Sincerely yours Francisco Tapia