Ruptime
This gives you the uptime and system load of shell servers.
centos7 up 20+11:40, 1 user, load 0.04, 0.06, 0.01 debian up 1:04, 1 user, load 0.16, 0.11, 0.14 fedora up 20+12:16, 0 users, load 0.13, 0.18, 0.17 ftp up 18:46, 0 users, load 0.56, 0.96, 0.81 mint up 18:46, 6 users, load 0.16, 0.09, 0.09 mxlinux up 20+12:14, 0 users, load 0.08, 0.09, 0.08 radius up 11+05:04, 3 users, load 0.10, 0.10, 0.09 scientific7 up 20+11:40, 0 users, load 0.00, 0.02, 0.00 ubuntu up 1+11:54, 5 users, load 2.94, 2.85, 2.75 zorin up 1:04, 0 users, load 0.15, 0.10, 0.08