+ Add a new reference filter for `docker images` [#27872](https://github.com/docker/docker/pull/27872)
### Runtime
+ Add `--experimental` daemon flag to enable experimental features, instead of shipping them in a separate build [#27223](https://github.com/docker/docker/pull/27223)
+ Add a `--shutdown-timeout` daemon flag to specify the default timeout (in seconds) to stop containers gracefully before daemon exit [#23036](https://github.com/docker/docker/pull/23036)
+ Add `--stop-timeout` to specify the timeout value (in seconds) for individual containers to stop [#22566](https://github.com/docker/docker/pull/22566)
+ Add a new daemon flag `--userland-proxy-path` to allow configuring the userland proxy instead of using the hardcoded `docker-proxy` from `$PATH` [#26882](https://github.com/docker/docker/pull/26882)
+ Add boolean flag `--init` on `dockerd` and on `docker run` to use [tini](https://github.com/krallin/tini) a zombie-reaping init process as PID 1 [#26061](https://github.com/docker/docker/pull/26061) [#28037](https://github.com/docker/docker/pull/28037)
+ Add a new daemon flag `--init-path` to allow configuring the path to the `docker-init` binary [#26941](https://github.com/docker/docker/pull/26941)
+ Add support for live reloading insecure registry in configuration [#22337](https://github.com/docker/docker/pull/22337)
+ Add support for storage-opt size on Windows daemons [#23391](https://github.com/docker/docker/pull/23391)
* Improve reliability of `docker run --rm` by moving it from the client to the daemon [#20848](https://github.com/docker/docker/pull/20848)
+ Add support for `--cpu-rt-period` and `--cpu-rt-runtime` flags, allowing containers to run real-time threads when `CONFIG_RT_GROUP_SCHED` is enabled in the kernel [#23430](https://github.com/docker/docker/pull/23430)
* Allow parallel stop, pause, unpause [#24761](https://github.com/docker/docker/pull/24761) / [#26778](https://github.com/docker/docker/pull/26778)
* Implement XFS quota for overlay2 [#24771](https://github.com/docker/docker/pull/24771)
- Fix partial/full filter issue in `service tasks --filter` [#24850](https://github.com/docker/docker/pull/24850)
- Allow engine to run inside a user namespace [#25672](https://github.com/docker/docker/pull/25672)
- Fix a race condition between device deferred removal and resume device, when using the devicemapper graphdriver [#23497](https://github.com/docker/docker/pull/23497)
- Add `docker stats` support in Windows [#25737](https://github.com/docker/docker/pull/25737)
- Allow using `--pid=host` and `--net=host` when `--userns=host` [#25771](https://github.com/docker/docker/pull/25771)
+ (experimental) Add metrics (Prometheus) output for basic `container`, `image`, and `daemon` operations [#25820](https://github.com/docker/docker/pull/25820)
- Fix issue in `docker stats` with `NetworkDisabled=true` [#25905](https://github.com/docker/docker/pull/25905)
+ Add `docker top` support in Windows [#25891](https://github.com/docker/docker/pull/25891)
+ Record pid of exec'd process [#27470](https://github.com/docker/docker/pull/27470)
+ Add support for looking up user/groups via `getent` [#27599](https://github.com/docker/docker/pull/27599)
+ Add new `docker system` command with `df` and `prune` subcommands for system resource management, as well as `docker {container,image,volume,network} prune` subcommands [#26108](https://github.com/docker/docker/pull/26108) [#27525](https://github.com/docker/docker/pull/27525) / [#27525](https://github.com/docker/docker/pull/27525)
- Fix an issue where containers could not be stopped or killed by setting xfs max_retries to 0 upon ENOSPC with devicemapper [#26212](https://github.com/docker/docker/pull/26212)
- Fix `docker cp` failing to copy to a container's volume dir on CentOS with devicemapper [#28047](https://github.com/docker/docker/pull/28047)
* Promote overlay(2) graphdriver [#27932](https://github.com/docker/docker/pull/27932)
+ Add `--seccomp-profile` daemon flag to specify a path to a seccomp profile that overrides the default [#26276](https://github.com/docker/docker/pull/26276)