It was originally intended for both V9 and V10, and quite a bit of work was done on it for V9, however, during the course of programming, it was discovered there were too may issues to overcome to make it for both versions and have it released in a reasonable timeframe. We also found more features in V10 that we could exploit that were not possible in V9. 64 bit being one of them. So we decided, unanimously, to make it for V10 only.