Linux on the desktop might mean freedom from software-licensing costs for some IT departments. But when it comes to evaluating desktop Linux’s TCO, it’s the human cost that is most important. According to industry research company IDC, the staff-related costs of system administration, support, development, and training typically amount to between 50 and 70 percent of the costs of the average enterprise application, when measured over a five-year period. By comparison, software costs for both client and server software total only 8 percent to 10 percent of TCO, IDC reports.