Very close. Our infrastructure to compile and execute your codes has been developed before Docker was ready. Therefore, we are not using it. We use a combination of overlayfs, ramfs, chroot and cgroups to do something very similar. The big difference is that we don’t have access to that nice system of images and layers provided by Docker… Thus, we have a big “jail” that contains all the tools needed to compile and execute the codes in 25 different languages. We have in our TODO list the migration of our system to docker, but I can’t tell you when.
The playgrounds is more recent and use a different stack based on docker images.