content: Illumos and its distribution SmartOS still have promise. They're a continuation of what used to be OpenSolaris, an old school UNIX derivative forked straight from Oracle Solaris, previously SunOS. You get LX branded zones, which is a sort of container providing binary compatibility with Linux on bare metal. You get zones in general, an in-kernel container for securely sandboxing whatever apps you want. ZFS is native. Dtrace also originated with that project.