Ruptime
This gives you the uptime and system load of shell servers.
centos7 up 15+18:43, 2 users, load 0.02, 0.10, 0.09 debian up 15+18:06, 4 users, load 6.97, 7.24, 7.23 fedora up 15+23:11, 0 users, load 0.06, 0.11, 0.09 ftp up 12+15:14, 0 users, load 6.95, 5.23, 3.73 mint up 10+06:01, 0 users, load 0.13, 0.21, 0.14 mxlinux up 15+23:12, 0 users, load 0.07, 0.08, 0.07 radius up 15+23:12, 2 users, load 0.06, 0.07, 0.08 scientific7 up 12+18:13, 1 user, load 0.03, 0.08, 0.08 ubuntu up 3:13, 9 users, load 4.09, 3.46, 3.26 zorin up 15+18:06, 9 users, load 0.10, 0.15, 0.16