DirectFB
Mir
Y Window System
Wayland
Xynth Window System
Metisse
XQuartz
xmodmap
kdiff3
Beyond Compare
WinMerge
Meld
Araxis Merge
DiffMerge
P4Merge
Devart Code Compare
DirectFB
kdiff3Mir - The purpose of Mir is to enable the development of user interfaces shells.
Beyond Compare - Beyond Compare allows you to compare files and folders.
Y Window System - Y Window System is a platform that allows you to improve the speed, working, and efficiency of the application in your operating system and helps you to increase the responsiveness of applications similar to any locally based app.
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
Wayland - Wayland is intended as a simpler replacement for X, easier to develop and maintain.
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.