EnCase is a suite of computer forensics software, commonly used by law enforcement. Its wide use has made it a de-facto standard in forensics. It is made to collect data from a computer in a forensically sound manner (employing checksums to help detect tampering).
For downloads and more information,
visit the EnCase homepage.
EnCase is a brilliant tool. The first two years that I used it I kept wishing for a GUI to bring it all together and make it easier to use. Then I realized just how brilliant the people are that put this work of art together. One has to work at this program to use it well but once you do, nothing is beyond your reach. It is designed for trained and certified people only, and that is alot of work. But if you want a career in Digital Forensics EnCase is where you want to go.
The latest EnCase Forensic v6 is 6.19.x, but is available only to existing customers.
The latest version is 7.0. It has undergone major modifications which unfortunately introduced bugs, incompatibilities, and general messiness, which makes it quite difficult to use and trust. The general impression is that it is little more than beta-testing level software. While the 6.x releases (considerably more stable) may have earned a mention on this list, release 7 does not -- at least not yet.