CUJO
Security Growler
Away Mode
WebARX
Mango Mirror
DRVR
Gravity scan
Turn Touch
kdiff3
Beyond Compare
WinMerge
Meld
Araxis Merge
DiffMerge
P4Merge
Devart Code Compare
kdiff3Security Growler - Menubar app which notify when various security events occur
Beyond Compare - Beyond Compare allows you to compare files and folders.
Away Mode - Protect your home with this awkward Alexa skill
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
WebARX - Website Protection, Managed Website Security & Website Monitoring
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.