NodeXL

"NodeXL is a free, open-source template for Microsoft® Excel® 2007, 2010 and 2013 that makes it easy to explore network graphs". NodeXl transforms user-input network edge list's into sophisticated graphs all within the familiar Excel environment. NodeXL can easily import or export graphs from GraphML, Pajek, UCINet, and matrix formats, and features direct connections to various social media platforms allowing users to simply create social networks in seconds. With flexible layouts, zoom functions, and scalability, NodeXL is easily manipulated to create a user-friendly environment.