> I'm hardly a connoisseur of DER implementations, but my understanding is that there are two main problems with DER. The first is that the format isn't really parseable without using a schema, unlike (say) XML or JSON.
That's not really the problem. The problem is that DER is a tag-length-value encoding, which is quite redundant and inefficient and a total crutch that people who didn't see XDR first could not imagine not needing, but yeah, they really didn't need it. That crutch made it harder, not easier, to implement ASN.1/DER.
XML is no picnic either, by the way. JSON is much much simpler, and it's true you don't need a schema, but you end up wanting one anyways.
That's not really the problem. The problem is that DER is a tag-length-value encoding, which is quite redundant and inefficient and a total crutch that people who didn't see XDR first could not imagine not needing, but yeah, they really didn't need it. That crutch made it harder, not easier, to implement ASN.1/DER.
XML is no picnic either, by the way. JSON is much much simpler, and it's true you don't need a schema, but you end up wanting one anyways.