> The people who wrote PB clearly knew ASN.1.

And your assumption is based on what exactly?

> It was the most famous IDL at the time.

Strange that at the same time (2001) people were busy implementing everyting in Java and XML, not ASN.1

> Do you assume they just came one morning and decided to write PB without taking a look at what existed?

Yes, that is a great assumption. Looking at what most companies do, this is an assumption bordering on prescience.

> Strange that at the same time (2001) people were busy implementing everyting in Java and XML, not ASN.1

Yes. Meanwhile Google was designing an IDL with a default binary serialisation format. And this is not 2025 typical big corp, over staffed, fake HR levels heavy Google we are talking about. That’s Google in its heyday. I think you have answered your own comment.