Parallel Password Recovery (RAR module) is a program for recovering passwords for RAR/WinRAR compressed files. It supports multi-core CPUs and GPUs, up to eight total in your machine to take full advantage of your hardware technology. It also supports brute-force and dictionary attacks.
The interface is simple. You can set the number of processing cores and GPUs (graphic cards) to be used by the application, and the priority of process from idle to faster (the latter will allocate 100% processor speed for the task).
The Password Definition File (PDF) is the file that contains the characters to be used in the process, e.g. lowercase and/or uppercase letters, numbers, symbols, etc., and the dictionary. It is a plain-text file that we have to create using something resembling the regular expressions used in programming languages. The PDF is a bit difficult to create, but for a professional tool like this, you can have more control over the password generation. You can find how to create this file with the help found on the official website.
You can also use the Password Definition Master utility to create the password definitions and dictionary. This utility guides you through the process with an easy interface, but notice that this is not as powerful as creating it manually.
The Demo version lets you work with up to four processors/cores and one GPU, and with passwords up to five characters long. Paid versions offer support for up to eight processors or eight GPUs, or any combination, depending on the license you buy. This program also supports the new CUDA technology (code name Fermi) present in Nvidia graphic cards.
This is a great utility in case you lost or forgot the password of the RAR file. It's fully customizable. The Password Definition Language lets you give the program some hints in case you remember part of the passwords. The program supports 2.x-3.x RAR versions, multi-volume, self-extracting, and encrypted files. It works on Windows 2000 / XP / Vista / 7 operating systems.