[notaplumber]

There's OpenNTPD which is maintained by the OpenBSD/OpenSSH developers. It has been poorly criticized for its focus on security rather than absolute precision, but it's more than adequate for most peoples timekeeping needs.

http://www.openntpd.org/

It has privilege separation, sandboxing and if your OS/distribution uses LibreSSL it implements HTTPS constraints.

http://man.openbsd.org/ntpd.conf.5

http://man.openbsd.org/ntpd.8

http://man.openbsd.org/ntpctl.8

[PhantomGremlin]

it's more than adequate for most peoples timekeeping needs

Yes it is. I'm on a cable modem and currently using OpenNTPD to talk to 5 NTP servers. My largest offset is currently 3.6 milliseconds. That's fine for general purpose computing. Anyone who needs better should probably buy some NTP or PTP hardware for his LAN.