Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
LiteSpeed Web Server - LiteSpeed Web Server (LSWS) is a high-performance Apache drop-in replacement.
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.