Below is a list of sites that offer tools and ways to crack passwords.The idea behind posting all these sites at one place is not to attract and promote users to try password cracking.The idea is to always remember ways and means to create and promote stronger passwords which can not be cracked.All these sites do have limitations to crack the stronger passwords and related info...
Ophcrack is a free Windows password cracker based on rainbow tables. It is a very efficient implementation of rainbow tables done by the inventors of the method. It comes with a Graphical User Interface and runs on multiple platforms.
Brutus is one of the fastest, most flexible remote password crackers you can get your hands on - it's also free. It is available for Windows 9x, NT and 2000, there is no UN*X version available although it is a possibility at some point in the future. Brutus was first made publicly available in October 1998 and since that time there have been at least 70,000 downloads and over 175,000 visitors to this page. Development continues so new releases will be available in the near future. Brutus was written originally to help me check routers etc. for default and common passwords
The source of independent information about cryptosystem weakness and password recovery.