DataWalk - DataWalk is a software platform to connect numerous large data sets, both external and internal, into a single repository for fast visual analysis.
Linkurious - Search and visualize your graph data through a simple web-based interface
SIREN.io - Siren is an investigative intelligence platform.
Maltego - Maltego is an open source intelligence and forensics application.
Netglub - Netglub, the really open source information gathering solution.
SpiderFoot - Open source intelligence (OSINT) automation tool.