kdiff3
Beyond Compare
WinMerge
Meld
Araxis Merge
DiffMerge
P4Merge
Devart Code Compare
thangs
LendList
LendPal
Catch & Release: Outdoorsman's Consignment
Pippit
LendingCrowd
Dayblizz
Who Has My Stuff
kdiff3
thangsBeyond Compare - Beyond Compare allows you to compare files and folders.
LendList - Never again forget what you borrowed from someone and keep track of what your friends borrowed from you (Android app). - raphaelm/lendlist
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
LendPal - Fast And Reliable Working Capital
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.
Catch & Release: Outdoorsman's Consignment - Niche app for the outdoors, sports & fitness enthusiast