The Unarchiver - Get the top application for archives on Mac. It's a RAR extractor, it allows you to unzip files, and works with dozens of other formats.

BuiltWith - Find out the technology behind websites

patool - patool is a portable command line archive file manager

Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.

ArKiwi - A lightweight and very fast file archiver, where you can add, compress, extract, delete, password protect, and blazing fast search all your files.

WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.