First fifty programs you need to make to master any computer programming language

Mirror TCP traffic on one port to multiple ports/destinations

Extract specific information from webpage. Run in standalone mode or as API.

Given an IP address, tells if this is a Cloudflare IP. Eg: https://api.code.express/cfip/104.31.122.34

Convert CIDR blocks to constituent IP addresses

Respounder detects presence of responder in the network.

A sub-domain reconnaissance written in golang

A SOCKS5 proxy implementation in Ruby. Use as a standalone proxy or build your MITM apps using this library