Tribblix is an operating system distribution derived from OpenSolaris, OpenIndiana, and illumos, with a retro style and modern components. The base kernel and commands are from illumos, with a few components currently repackaged from OpenIndiana (mostly X11, some other oddments); pretty much everything else has been rebuilt from scratch.
It is very much a traditional system. Software is distributed as SVR4 packages, lightweight window managers are preferred over heavy desktop environments, the primary desktop option is Xfce, and MATE and Enlightenment are also available, plus many others. The system is flexible, fast, and familiar to those who've used Solaris in the past, while shipping modern software on the solid foundation it's based on.
Tribblix isn't just a spin or repackaging of another illumos distribution. It's a completely independent distribution that, while sharing the key illumos technologies such as ZFS, zones, DTrace, and SMF, has been essentially built from scratch, with its own build and packaging system.
A version for SPARC is also available. Due to limited availability of hardware both for myself and the illumos community as a whole, hardware support might be limited. This was bootstrapped with OpenSXCE, and doesn't yet have the full range of packages that are available for x86 systems.
What's in the name? It may seem rather vain, but if I were to choose a name from scratch I wouldn't have come up with this and would probably have gone for some obscure solar-powered pun. However, at one of the OpenSolaris summits we took part in a Go Game, and one of the questions was:
Which of the following is not an OpenSolaris-derived distribution:
I'm not sure that whoever set the question knew how close that was to the name of someone on the project, but that was how the name became planted in my consciousness.