The Autopsy Forensic Browser is a graphical interface to the command line digital investigation analysis tools in The Sleuth Kit. Together, they can analyze Windows and UNIX disks and file systems (NTFS, FAT, UFS1/2, Ext2/3).
The Sleuth Kit and Autopsy are both Open Source and run on UNIX platforms. As Autopsy is HTML-based, you can connect to the Autopsy server from any platform using an HTML browser. Autopsy provides a "File Manager"-like interface and shows details about deleted data and file system structures.
More details and features are listed here.