The present invention relates to the design-time and run-time environments of instruction processors implemented in re-programmable hardware. In one aspect the present invention provides a design system for generating configuration information and associated executable code base on a customization specification, which includes application information including application source code and customization information including design constraints, for implementing an instruction processor using re-progammable hardware, the system comprising: a template generator; an analyzer; a compiler; an instantiator, and a builder. In another aspect the present invention provides a management system for managing run-time re-configuration of an instruction processor implemented using re-programmable hardware, comprising: a configuration library; a code library; a loader; a loader controller; a run-time monitor; an optimization determiner; and an optimization instructor.