In the early 1990's, I used Tripwire on Unix systems I was administering. Tripwire was very helpful in maintaining the configuration of the systems, providing assurance of system integrity. Most of all, it helped keep track of well intentioned but otherwise inadequately documented changes to the system.
More recently, when I again became responsible for the administration of Unix system, I looked up tripwire, but the license had changed. The software was no longer free. So I searched for alternatives and found AIDE.
When I had trouble understanding how the AIDE configuration rules worked, I started reading the source code. Initially, I just added comments as I came to understand sections, then I started making changes to the code, and after a few months the accumulated changes were quite significant.
After considering various approaches, I decided that the best thing to do with my modified code was to make it available to the community. I would be very happy if what I have done was folded back into AIDE, or was useful to anyone in any way. As I benefited so much from the free release of AIDE, it didn't seem right to keep what I had done to myself.
The name is changed to File Attribute Monitor to avoid confusion. Much of the code is rewritten, and barely tested. If you consider using this software, please test it carefully and use it at your own risk.