Recon NG is a full-featured reconnaissance framework designed with the goal of providing a powerful environment to conduct open source web-based reconnaissance quickly and thoroughly.
It has a look and feel similar to the Metasploit Framework, reducing the learning curve for leveraging the framework. However, it is quite different. Recon-ng is not intended to compete with existing frameworks, as it is designed exclusively for web-based open source reconnaissance. If you want to exploit, use the Metasploit Framework. If you want to social engineer, use the Social-Engineer Toolkit. If you want to conduct reconnaissance, use Recon-ng! See the Wiki to get started.
It is a completely modular framework and makes it easy for even the newest of Python developers to contribute. See the Development Guide for more information on building and maintaining modules.