public access unix systems

a non-exhaustive list of active systems as of 2019

from Pubnix History Project
       Public Access UNIX Systems (PAUS) are a type of server that provide
       various services to a multi-user community.  They first began in the
       early 1980's and continue today. Early servers ran various flavors of
       UNIX, hence the name Public Access "UNIX" Systems, but later generations
       saw a large mix of Unix-variants and, of course, GNU/Linux.  To         
       recognize the many different operating systems online today, these
       systems are increasingly referred to generically as "pubnixes".