Beyond Compare - Beyond Compare allows you to compare files and folders.
Skuuudle - Discover, match and monitor your eCommerce competitors.
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
Price2Spy - Price2Spy is a price monitoring, pricing analytics, and repricing tool, meant to help eCommerce professionals keep an eye on their competitors or retailers.
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.
BuiltWith - Find out the technology behind websites