[SpiderFoot v2.0] The Open Source Footprinting tool

SpiderFoot is a free, open-source footprinting tool, enabling you to perform various scans against a given domain name in order to obtain information such as sub-domains, e-mail addresses, owned netblocks, web server versions and so on. The main objective of SpiderFoot is to automate the footprinting process to the greatest extent possible, freeing up a penetration tester’s time to focus their efforts on the security testing itself.

Main features

Fast, Easy to Use
Highly Configurable
For Windows & Linux
Create your own modules in Python

New in this release, which is actually a complete re-write of the version from 2005(!):

Now runs on Windows as well as Linux, Solaris, *BSD (basically anything with Python should be fine)
Scans are even more configurable than before
All scan data stored locally in an SQLite database for querying, reporting and analysis
Many more scans/tests included (GeoIP, URL linkage, web technology, port scans…)
You can now easily extend functionality by writing your own modules in Python
Completely new user interface, which is now entirely web-based
Configuration state is stored between runs
Scanning can be remotely controlled