Comment by spacechild1

> It seems like a huge technical factor holding back a stable ABI is the C compiler itself.

Not really. Every OS has a stable C ABI, otherwise there would be no stable OS API functions and no application plugin APIs. The actual reason seems to be that they simply do not want to commit to a stable ABI/API so they are free to make breaking changes and remove outdated APIs. Fair enough, but don't blame it on the compiler!