No matter how powerful a computer you or your end user has, faster software is always desirable. For one, we live in an era where time is very valuable and technology is here to empower us, not to set limits on what we can or wish to do. Furthermore, the responsiveness of an application to its user is a crucial benefit and increasingly important differentiator between ordinary software and superior software. Responsiveness of software is generally defined as its ability to react fast, to provide guidance and feedback and to allow users to cancel or redirect time-consuming operations.