Hey all! Just a few questions: can the open source tools/work flows be used with proprietary PDKs as well? How mature is the ecosystem for new startups to use open source EDA tools not only for taping out prototypes but for production as well?

My personal thoughts: The digital open-source tools (OpenROAD, Yosys) are ready for tapeout with many proprietary PDKs (above 7nm) and in fact have already done so. They are good for prototyping, although production is at your own risk. It very much depends what your production requirements are and what technology you are targeting. I can't speak to the robustness of analog/AMS tools for proprietary PDKs.