Since 1.12.0, experimental is not a nightly build anymore but is a different channel that follows the same release scheduled than stable. As it stands now, experimental is just a super-set of the stable release, and should not be considered "beta".

TL;DR: experimental is a stable release, with a couple features which API stability we don't guarantee.

Proposal

• Change experimental to be a runtime flag (daemon configuration, environment variable, ...?) rather than a compile-time build tag.
• Allow the client to discover whether the daemon it's talking to has experimental enabled, and display the extra experimental commands/flags accordingly. Note that this extra round-trip will likely be required to solve API/CLI version mismatch #25498 anyways.
• Remove traces of experimental in build scripts (e.g., DOCKER_EXPERIMENTAL environment variable).
• Find a transition path for https://experimental.docker.com (e.g., should it install a regular daemon with the experimental flag enabled?).