@swetland @raggi @david_chisnall oh yeah that would work!
@whitequark @raggi @david_chisnall On the userspace side code could try to open /dev/content-negotiation, try the direct ioctls (once they exist), and fall back to good 'ol plaintext if neither are available.
The down side of that approach is that it interacts poorly with sandboxing. Now every process that you might invoke interactively needs permission to access a new path.