TestDisk is OpenSource software and is licensed under the terms of the GNU General Public License (GPL).
TestDisk is a powerfull FREE data recovery tool it can run under windows as well as Linux.
Here's what their site says,
* Fix partition table, recover deleted partition
* Recover FAT32 boot sector from its backup
* Rebuild FAT12/FAT16/FAT32 boot sector
* Fix FAT tables
* Rebuild NTFS boot sector
* Recover NTFS boot sector from its backup
* Fix MFT using MFT mirror
* Locate ext2/ext3 Backup SuperBlock
* Undelete files from FAT, NTFS and ext2 filesystem
* Copy files from deleted FAT, NTFS and ext2/ext3 partitions.