Network
W

w -- provides a summary ot the current activity on the system (uptime), plus details of who is logged in and what each user is doing
w -h does the same except the heading is suppressed

The only differences among the systems is in the display format, mostly in the naming of the connections

FreeBSD
 8:01 PM up 3:14, 2 users, load averages: 0.27, 0.14, 0.07
USER TTY FROM LOGIN@ IDLE WHAT 
joev0-6:27PM-
jimmyv2-6:27PM--sh(sh)


OpenBSD
 8:01 PM up 3:14, 4 users, load averages: 0.27, 0.14, 0.07
USER TTY FROM LOGIN@ IDLE WHAT 
joeC0-6:27PM0
jimmyC2-8:21PM13-sh(sh)
judyp0freeserve8:21PM0-sh(sh)
jeffp0158.222.111.888:21PM0-sh(sh)


NetBSD
8:01 PM up 3:14, 1 user, load averages: 0.27, 0.14, 0.07
USER TTY FROM LOGIN@ IDLE WHAT 
joeco-6:27PM0


Linux
8:01 PM up 3:14, 2 users, load averages: 0.27, 0.14, 0.07
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT 
joetty1-6:27PM0.00s0.04s0.00s
jimmytty2-8:21PM4.00s0.00s0.00s-sh(sh)


see finger finger
ps ps
uptime uptime
who who