changetrack is a program to monitor changes to files. If files are modified one day, and the machine starts working incorrectly some days later, changetrack can provide information on which files were modified, and help locate the problem. Changetrack will also allow recovery of the files from any stage.
snowdrop is a steganographic text document and C code watermarking tool that uses redundant, tamper-evident and modification-proof information embedded in the content itself, instead of the medium, to simplify tracking of proprietary code leaks, sensitive information disclosure, etc.
F-Watch is a kernel module that reports changes on files to /dev/fwatch. It hooks into the sys_calls and does not require a kernel patch. To activate watching for certain events, users need to run ioctl to register the wanted events; examples are in the src dir. Ioctl can be used during runtime to individually change the required events.