SIREN.io - Siren is an investigative intelligence platform.
SpiderFoot - Open source intelligence (OSINT) automation tool.
Netglub - Netglub, the really open source information gathering solution.
Sentinel Visualizer - Link Analysis, Data Visualization, Geospatial Mapping, and Social Network Analysis (SNA) with Sentinel Visualizer
sn0int - sn0int is a semi-automatic OSINT framework and package manager
dradis - Dradis is the open-source reporting and collaboration tool for IT security professionals.