To amplify my previous statement, I think this is a great piece of work! Vladimir is to be commended. I also think that it may well get substantially faster as Vladimir continues to make minor algorithmic modifications. Jon Bentley has made many fine suggestions that Vladimir will try out.There are also some lower-level performance tweaks that may well yield improved performance (e.g., eliminate the div parameter from dualPivotQuicksort, eliminate the division from algorithm). It is, of course, possible that this performance work won't yield significant benefits, but I suspect otherwise. Josh
P.S. When all of this is done, the code could use some minor reformatting to match JDK standards, but I wouldn't worry about this until the performance work is done.