Ophcrack is a Windows password cracker based on a time-memory trade-off using rainbow tables. It is a very efficient implementation of rainbow tables done by the inventors of the method. It recovers 99.9% of alphanumeric passwords in seconds.It comes with a GTK+ Graphical User Interface and runs on Windows, Mac OS X (Intel CPU) as well as on Linux. Download the MacOS and Linux versions from the developerТ‘s website.