These images based on Debian Stretch, the 4.9.x RT-PREEMPT kernel, and a released version of LinuxCNC 2.7.x.
They can be used as a live USB/DVD for latency testing and installed to a hard drive.
We are in the process of making these the official recommended images for LinuxCNC 2.7, you can track the progress of that task on github.
For more information about the image building process, see this github repository.
If you've fetched an earlier version (e.g., ...-r1.iso) then you can fetch a newer version efficiently using zsync -i ...-r1.iso http://....-r2.iso.zsync.
You can check the integrity of your downloaded images with e.g., sha256sum --check SHA256SUMS
Name Last modified Size Description
Parent Directory - linuxcnc-stretch-uspace-amd64.iso 2018-10-27 17:57 1.2G linuxcnc-stretch-uspace-amd64.iso.zsync 2018-10-27 11:17 2.5M linuxcnc-stretch-uspace-i386.iso 2018-10-27 17:52 1.3G linuxcnc-stretch-uspace-i386.iso.zsync 2018-10-27 11:13 2.6M