SpiderFoot - Open source intelligence (OSINT) automation tool.
sn0int - sn0int is a semi-automatic OSINT framework and package manager
Maltego - Maltego is an open source intelligence and forensics application.
DataWalk - DataWalk is a software platform to connect numerous large data sets, both external and internal, into a single repository for fast visual analysis.
OWASP Amass - An advanced open source tool to help information security professionals perform network mapping of attack surfaces and external asset discovery using open source information gathering and active reconnaissance techniques!
LinkScope Client - Repository for the LinkScope Client software.