RISC-V Linux port has been accepted into Linus’ tree and is slated to release as part of 4.15. While this is a major milestone for RISC-V, they’re far from done in Linux kernel land and there’s a whole lot of work left to be done in userspace.
RISC-V is an open instruction set architecture (ISA) that began in 2010 at the University of California, Berkeley, based on established reduced instruction set computing (RISC) principles, it can be freely used for any purpose, permitting anyone to design, manufacture and sell RISC-V chips and software.