File and Directory Synchronization Tool
This tool lets a user compare two directories side-by-side to see which files and subdirectories contain new or out-of-date

System::Archiving::Backup

tkdiff
tkdiff is a graphical front end to the diff program. It provides a side-by-side view of the differences between two files

Software Development

schema-compare
Schema-compare is a PHP script that will compare two database schema's and show the differences side-by-side. It will

Database

ResBundleEdit
ResBundleEdit is a localization tool for Java resource bundles. It shows several languages side-by-side, includes search

Software Development
Text Editors::Text Processing

Diffr file comparer
Diffr compares two source files and graphically displays the differences side-by-side. Sections of differences are highlighted

Software Development

Meeting Room Booking System
MRBS is a system for multi-site booking of meeting rooms. Rooms are grouped by building/area and shown in a side-by-side

Communications
Internet::WWW/HTTP
Office/Business::Scheduling