These are not official, stable releases, these are automated builds from the master Git branch for testing. Builds are performed on OS X 10.11.6, Xcode 8.2.1, using the build script provided in the project repository.
There is a download-and-install script available to get and install the tools in one step. Run the following command in a terminal session (once you've audited the script yourself):
curl https://munkibuilds.org/latest3.sh | sh
Maintained by Tim Sutton.