NPL Computer Time Services - Truetime/NPL Phoneclock
- Synchronization to UK time by telephone. This is the UK's national measurement laboratory.
- http://www.npl.co.uk/server.php?show=ConWebDoc.995

Configuring Microsoft's Win32Time service.
- Useful information on how to configure the win32time service which ships with Microsoft's server products.
- http://support.microsoft.com/kb/314054

Meinberg USA
- Manufacturer of hardware Network Time Servers (NTP) for IPv4 and IPv6 networks.
- http://www.meinberg-usa.com/

Timeserver description on Wikipedia
- Some useful information about the basics of what a time server is.
- http://en.wikipedia.org/wiki/Timeserver

PresenTense Time Server
- Multi protocol time server which synchronizes itself with any true time source, including GPS via rs-232 com ports and then acts as a time server for all network clients. PresenTense Time Server ships with drivers for many reference clocks including Spect
- http://www.bytefusion.com/products/ntm/ntm.htm

Open NTPD
- A mainly BSD implementation of the Network Time Protocol.
- http://www.openntpd.org/

Spectracom: GPS hardware NTP and SNTP clocks.
- Manufacturer of hardware GPS clocks and NTP/SNTP servers. Legally traceable time.
- http://www.spectracomcorp.com

TimeTools
- Specializes in computer and network timing solutions. Using NTP for network time synchronisation in conjunction with MSF, DCF-77 and GPS time sources.
- http://www.timetools.co.uk

Beagle Software
- NTP, Daytime timeserver and client software and hardware.
- http://www.beaglesoft.com

Galleon Systems
- Provider of NTP time synchronisation solutions using the MSF radio signal and GPS satellites.
- http://www.galleon.eu.com/

Symmetricom, Inc.
- Manufacturer of time and frequency synchronization equipment, including NTP Servers.
- http://www.symmttm.com/products_network_timing.asp

NTP with TymServer
- Hardware NTP time server manufacturer.
- http://www.tymserve.com

EndRun Technologies
- Provider of time and frequency equipment including NTP Servers.
- http://www.endruntechnologies.com/

ELPROMA NTP Servers
- European manufacturer of NTP Time Servers.
- http://www.ntp-servers.com/

Brandywine Communications
- Offers advanced off-the-shelf and custom hardware time and frequency solutions including Network Time Protocol servers.
- http://brandywinecomm.com/

Network Time Protocol (NTP) Project.
- The official page for the NTP Project. Contains information about the project, reference implementations of the protocol and software links. Also links to the pool of public NTP servers.
- http://www.ntp.org

NIST Web Clock
- Shows the official US time in each time zone.
- http://www.time.gov/