The famous password cracking tool L0PHTCRACK (or LC for short) is now back on the market, upgraded to LC6. The tool was acquired by Symantec as part of its purchase of @Stake in 2004, who had developed the tool for audit and consulting engagements.
Symantec ended formal support for LC in 2005. However, a clause in the acquisition contract gave the developers an option to reacquire the tool in such circumstances, and several former members of the hacker high priest group L0pht Heavy Industries have exercised that option. The new site for LC6 is here, where it is marketed as a password audit and recovery tool.
The basic version of LC6 at $295 (called Professional) includes password assessment & recovery, dictionary and brute force support, international character sets, password quality scoring, Windows & Unix support, remote system scans and executive reporting. The Professional version supports up to 500 accounts. Other versions at double or four times the cost support an unlimited number of accounts, installed on multiple machines.
Note that LC6 is subject to United States export controls.