Designing tools for interoperability has become mandatory for the EDA industry. Standards and open architectures allow internal CAD teams to create the ‘glue software’ to quickly integrate a new tool into the flow. Published APIs help EDA vendors create a tight integration with popular tools and flows. Synopsys’ Custom Designer’s support for the OpenAccess database and ClioSoft’s Universal DM adaptor enable version control and management of design libraries with just a simple configuration file. The open API and customizability built into Custom Designer and SOS may allow Synopsys and ClioSoft to create a tighter integration in the future. Authors of both companies explain how they did it.