Nmap
Description: Nmap is an open source network discovery and security auditing tool. It is used to discover hosts and services on a network and to detect potential vulnerabilities.
Type: software
Pricing: Free
phpList
Description: phpList is an open source newsletter and email marketing software. It allows you to easily create, send, and track email newsletters, announcements, notifications, and more to a list of subscribers.
Type: software
Pricing: Open Source