OS base for linuxcnc beyond support date

I downloaded and installed linuxcnc-2.7.14-wheezy.iso. The OS base is out of support and I was unable to install or update packages.
Is there an iso image that is still within support?
If not Is there a linuxcnc package configured for a later OS that can be installed separately?

(as an aligened but separate note, linuxcnc is documented to requre linux RT kernels. Is this strictly necessary or if one is sensible about whatesle else is running will a standard kernel work? )
Thank you, Dan

The current official ISO is based on BUSTER:
linuxcnc.org/downloads/

And yes, the RT kernel is required. Note that this ISO is a fairly bare debian install which usually works fine for most machine controllers. However if you need driver support for say WiFi dongles there is also a less easy install procedure for LinuxMint that is based on Ubuntu.
forum.linuxcnc.org/9-installing-linuxcnc...stall?start=0#175816