This page gives an overview of upstream projects. If you miss information or find mistakes, please edit.
FreeBSD has a weaker sense of maintainership than many open-source projects. However, the primary contributors are:
FreeBSD major releases are approximately every two years, with minor releases every year and interim security patches as needed.
RV64G is supported for several popular hardware, emulated and FPGA-based platforms as a Tier 2 platform. Various feature additions and performance optimisation opportunities exist. See the upstream wiki page linked above for more details.
The Linux kernel has been merged mainline in the 4.15 merge window in November 2017.
Since then a range of Distributions have RISC-V ports. E.g.:
The Linux kernel supports RV64G as well as RV32G.
Work is in progress adding the port, with the first commit made on 23rd April 2021.