what roadblocks still exist for further open source silicon development? for example: • how did google convince skywater/glofo to open up some PDKs? what does it take to get more? what about leading edge and near leading edge? • what would it take for current/next-gen tech to be developed in the open? (e.g. 28/56/112G SerDes, various PHYs, PCIe 4/5/6, ...) • is there anything you get in a closed PDK that isn't (and will never be) available in an open PDK?

1. Paid money for releasing it. It also benefitted sky/glofo as it gets google to pay for more tapeouts 2. Money 3. Not gonna happen, see below 4. Money And see below 5. All of the leading teach is not available due to US export restrictions. You cant just post bleeding edge tech on the internet. As people under sanctions might use the tech (China, Russia, Iran, etc)

does 5 apply to tech developed outside the US?

Depends. If it contains US tech, it is restricted

As far as I have understood the export restrictions, those are only for proprietary licensed things. As soon as some tech is published on the internet as OpenSource, it isn't export restricted.