I used to run the FreeBSD box for sendmail.org.  When I left that job in 2001 it had already been running for 2+ years.<p>Considering that the datacenter it was in is now the Dropbox office, I&#x27;m guessing it had to be shut down and moved at some point, but 2+ years seemed like a really long time even then!<p>FreeBSD is just really good at lasting forever.