Robert Probst invented the cubicle in the 1960s while trying to design better workspaces for "knowledge workers." He created the Action Office system which featured attractive, mobile furniture meant to keep workers moving and thinking. In the past 40 years, office design has struggled with balancing collaboration and individual focus. Open offices are popular but many workers feel distracted. New designs aim for a middle ground with some open space and private areas. Technology companies in particular are experimenting with flexible workspaces to meet changing needs for teamwork and solitary work.