How to: Fingerprint
https://github.com/urbanadventurer/WhatWeb
# WhatWeb identifies websites. Its goal is to answer the question, "What is that Website?". WhatWeb recognises web technologies including content management systems (CMS), blogging platforms, statistic/analytics packages, JavaScript libraries, web servers, and embedded devices.
```whatweb -a 4 -U 'Mozilla' -c 'NAME1=VALUE1; NAME2=VALUE2' -t 20 www.example.com```

https://builtwith.com
# Find out what websites are Built With.

https://www.wappalyzer.com
# Identify technologies on websites.

https://github.com/s0md3v/wappalyzer-next
# This project is a command line tool and python library that uses Wappalyzer extension (and its fingerprints) to detect technologies.
```wappalyzer -i https://example.com```

https://webtechsurvey.com
# Discover what technologies a website is built on or find out what websites use a particular web technology.

https://portswigger.net/bappstore/c9fb79369b56407792a7104e3c4352fb
# Software Vulnerability Scanner Burp Extension

https://github.com/GrrrDog/weird_proxies
# It's a cheat sheet about behaviour of various reverse proxies and related attacks.