I would assume GNU/Linux, Android, Solaris because of the companies involved. Am I correct?
It really would be interesting to know why Oracle got involved, though, since their involvement is not the universal sign of pending success for an open source project.
sometimes it is writing software that interoperates (bi and the like), other times it is direct need (java in the case of google and oracle, and i'm sure at least some backend systems).
Sooner or later they will port Android to it so it can be used in smart phones and tablets.
Being involved in alternative architectures seems like a sound defensive move.
> Currently RISC-V runs Linux and NetBSD, but not Android, Windows or any major embedded RTOSes. Support for other operating systems is expected in 2016.
No mention of Solaris, so I assume that would be forthcoming?