If you're into Docker, you may also be interested in linux containers more generally, and there's a new Linux Foundation collaborative project called the Open Container Project you should check out. The number of logos from supporting companies and or projects is impressive and encouraging.
Containers have been around for quite a number of years, but are gradually becoming a more and more viable alternative to other types of virtualisation or resource management for servers.
Tenko Nikolov spoke about Siteground's efforts with containers, and that they'll be a part of the aforementioned project. He said they've written some of their own tools and patches to make containers more secure, and will be contributing the progress they've made in their own implementations back for others to take advantage of.