Fig (Fast, isolated development environments using Docker) -- http://www.fig.sh
Sandstorm (Personal Cloud Sandbox /!\ uses LXC, not docker, but it's so nice) -- https://sandstorm.io/
ns-enter (no more ssh, enter name spaces of container) by @jpetazzo
Squid-in-a-can (in case of proxy problem) by @jpetazzo
docker-gen (Generate files from docker container meta-data) by @jwilder
registrator (Service registry bridge for Docker) by @progrium
Boot2Docker (docker for OSX and Windows) -- http://boot2docker.io/

Shipyard (Composable Docker Management) -- http://shipyard-project.com/
Panamax (Docker Management for Humans) -- http://panamax.io/
Docker Registry
Docker Registry Web (A web UI for easy private/local Docker Registry integration) by @atc-
Flynn (A next generation open source platform as a service (PaaS)) -- https://flynn.io/
Deis (Your PaaS, your rules) -- http://deis.io/
Gaudi (Gaudi allows to share multi-component applications, based on Docker, Go, and YAM) -- http://gaudi.io/
CoreOS (Linux for Massive Server Deployments) -- https://coreos.com/
Dokku (Docker powered mini-Heroku in around 100 lines of Bash)
- dokku-alt (Dokku fork with Dockerfile support, database plugins, ACL and more)

Slides

Videos

Orchestrating Docker containers in production using Fig (7:11)
Development Environments with Fig by Aanand Prasad (17:58)
Docker in Production by @jpetazzo (36:05)
Docker: How to Use Your Own Private Registry (15:01)
Contributing to Docker by Andrew "Tianon" Page (InfoSiftr) (34:31)
Performance Analysis of Docker - Jeremy Eder (1:36:58)
Docker and SELinux by Daniel Walsh from Red Hat (40:23)
Immutable Infrastructure with Docker and EC2 by Michael Bryzek (Gilt) (42:04)
Ansible and Docker HP (32:38)