TestBox - Test drive your software options before you buy
Siftery - Share products your company uses and get personalized recommendations
Product Comparisons - Compare any 2 software products
Stackshare - StackShare is a comprehensive website that gives its users the chance to organize and share their technology stack with the rest of the community.
Insider Company Comparisons - Compare hundreds of top tech companies all in one place
WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.