.NET Core runtime.
For EL7:
cd '/etc/yum.repos.d/'
curl 'https://copr.fedorainfracloud.org/coprs/scx/coreclr20-opt/repo/epel-7/scx-coreclr20-opt-epel-7.repo' > 'scx-coreclr20-opt-epel-7.repo'
This is a companion discussion topic for the original entry at https://copr.fedorainfracloud.org/coprs/scx/coreclr20-opt/