OrgOrgChart by Justin Matejka & George Fitzmaurice

The OrgOrgChart (Organic Organization Chart) project looks at the evolution of a company's structure over time. A snapshot of the Autodesk organizational hierarchy was taken each day between May 2007 and June 2011, a span of 1498 days.
Each day the entire hierarchy of the company is constructed as a tree with each employee represented by a circle, and a line connecting each employee with his or her manager. Larger circles represent managers with more employees working under them. The tree is then laid out using a force-directed layout algorithm.