WAN Optimization Controllers (WOCs) have become the de rigueur solution for improving performance over Wide Area Network (WAN) links. Projects such as Data Center (DC) consolidation, branch office consolidation, application centralization, DC-to-DC backup and replication, mobile work forces, and application centralization, to name a few, are helping to drive more traffic over WAN links. The problem is that WAN links have traditionally been both expensive and bandwidth constrained. In some cases, upgrading the links is not even an option, for example: in foreign deployments in developing countries, mobile workforces, temporary worksites with no high-speed connectivity options, or sites serviced through satellite links. This presents a problem for both the enterprise and service providers alike. The success of players in this market is testament to the need for the technology, and yet practitioners are faced with a dizzying array of options brought to market under the general category of WAN Optimization. This Enterprise Management Associates (EMA) Radar Report reviews thirteen providers of WAN Optimization Controller (WOC) solutions and compares their ability to deliver basic and advanced optimization benefits across a range network and application technologies.