One software license is required per machine.
Server - Chart FX for Reporting Services server components are licensed on a per-server basis for deployment, regardless of the number of processors (CPU's) in that server. The basic package includes one (1) Server License for deployment on a Production Server and one (1) Designer License.
Designer - Chart FX for Reporting Services design-time components are licensed on a per-developer basis. The license agreement permits you to use one (1) copy of these components on a single computer. If you need to install design-time components on more than one computer, you need to obtain an additional designer license for each computer.