It has the capability to directly download membership data from many popular social networks. This data is processed and the program can calculate network characteristics parameters. It also draws a network connectivity diagram. A brief overview of the use of the program is shown in the video below by the the program creator:
I created a network visualization for the people I am connected on the twitter. First I used NodeXL's capability to download data directly from Twitter. The used the program's capability to create the following Network visualization diagram.
Click on the image for an enlarged view.
Right now these plots are restricted to only one social network at a time. Also, the social networks put limits on how much and what kind of data can accessed from their website.
NodeXl is gaining popularity among academics. A number of instructors have been using to help teaching social network analysis. A book entitled " Analyzing Social Media Networks with Microsoft NodeXL Book" will be published in few months time. The outline of the book can be obtained here http://bit.ly/cCFEXD