SIREN.io - Siren is an investigative intelligence platform.
Lampyre - Lampyre - an efficient data analysis and OSINT multi-tool for everyone.
SpiderFoot - Open source intelligence (OSINT) automation tool.
Sentinel Visualizer - Link Analysis, Data Visualization, Geospatial Mapping, and Social Network Analysis (SNA) with Sentinel Visualizer
TLOxp - TLOXP
Maltego - Maltego is an open source intelligence and forensics application.