This presentation discusses intellectual property (IP) core reuse for SoC design, and looks at whether it has been a success or a failure. IP reuse is ubiquitous, but it needs stability (allowing the correct specification of the IP and making sure it is right-first-time). There are pressures to expand both market size and value. Semiconductor processes, customer roadmaps and design libraries will never be stable, so the IP design methodology must be able to adapt; this involves design for change. IP is ideas, methods, algorithms and test benches - not blocks, circuits and libraries.