Ruptime
This gives you the uptime and system load of shell servers.
centos7 up 42+04:55, 3 users, load 0.06, 0.04, 0.04 debian up 26+00:11, 6 users, load 2.08, 2.10, 2.12 fedora up 42+09:26, 0 users, load 0.20, 0.17, 0.10 ftp up 19+00:55, 0 users, load 0.71, 0.57, 0.64 mint up 36+16:13, 0 users, load 0.11, 0.07, 0.07 mxlinux up 42+09:24, 0 users, load 0.17, 0.14, 0.10 radius up 42+09:24, 2 users, load 0.02, 0.07, 0.08 scientific7 up 39+04:28, 2 users, load 0.00, 0.02, 0.00 ubuntu up 12+15:16, 8 users, load 0.10, 0.16, 0.34 zorin up 42+04:18, 6 users, load 0.21, 0.11, 0.04