If you follow the latest news about our in-memory cache technology we announced to provide an open source release for Terracotta, so you can use now Terracotta Server 4.3 OSS release for distributed caching, with offheap storage, including Ehcache and Quartz.
So, great news for the community, you can download it from here Terracotta Server Open Source Kit
Following this awesome news, one of our engineers http://blog.dahanne.net/ have publish a new Docker image containing the TS OSS, and it explains how to run it. You can read it from here, Docker image definition for Terracotta Server (docker.com)
You need Docker version 1.9.1 and onwards and Docker machine at least 0.5.0
Enjoy!

