Ruptime
This gives you the uptime and system load of shell servers.
centos7 up 50+16:28, 1 user, load 0.27, 0.15, 0.10 debian up 34+11:44, 4 users, load 0.10, 0.19, 0.16 fedora up 50+20:59, 0 users, load 0.04, 0.08, 0.07 ftp up 5+15:13, 0 users, load 0.75, 0.68, 0.67 manjaro up 2+09:40, 0 users, load 0.00, 0.00, 0.00 mint up 45+03:46, 0 users, load 0.10, 0.06, 0.08 mxlinux up 50+20:57, 0 users, load 0.13, 0.07, 0.01 radius up 50+20:57, 1 user, load 0.04, 0.06, 0.03 scientific7 up 47+16:01, 1 user, load 0.07, 0.03, 0.01 ubuntu up 2+03:10, 3 users, load 0.01, 0.11, 0.14 zorin up 50+15:51, 7 users, load 0.07, 0.07, 0.03