Not really recently. Both were implemented almost simultaneously in circa June 2018. https://github.com/AkihiroSuda/docker/commit/588a4e91fc8cb99af040dcde795ba

Not really recently. Both were implemented almost simultaneously in circa June 2018. https://github.com/AkihiroSuda/docker/commit/588a4e91fc8cb99af040dcde795ba6722a162127 https://github.com/AkihiroSuda/docker/commit/588a4e91fc8cb99... https://github.com/containers/podman/commit/19f5a504ffb1470991f331db412be456e41caab5 https://github.com/containers/podman/commit/19f5a504ffb14709... Rootless Docker wasn't merged/released until Docker 19.03, though , but still it is already nearly 4 years old.