GPS Receivers:
    Jupiter-T  (aka Zodiac)
    Furuno GT-8031 ($PFEC commands ... not yet tested)
    GPSD interface (mainly a Linux thing - provides a shared read-only
               interface to numerous GPS devices)
    Motorola binary 
    NMEA
    Sirf binary
    NVS binary (115200:8:N:1)
    Trimble TSIP binary receivers
    Trimble TAIP receivers
    Trimble SV6/SV8/ACE-III
    Trimble Accutime / Palisade receivers
    Ublox UBX binary 
    Venus mixed binary / NMEA

 GPSDO's (GPS disciplined oscillators):
    Brandywine GPS-4 GPSDO
    DATUM STARLOC II GPSDO - inferior wannabe Thunderbolt - buggy firmware
    Jackson Labs LTE Lite
    Lucent RFTG-m GPSDO
    Lucent KS24361 REF0/Z3811A  Z3812A
    NEC GPSDO ... STAR-4 compatible at 115,200 baud
    UCCM - Trimble / Symmetricom GPSDOs
    Oscilloquartz STAR-4 GPSDO (management interface)
    Oscilloquartz OSA-453x GPSDO
    SCPI - Nortel telecom GPSDOs like NTWB and NTPX in SCPI mode
    SCPI (Z3801A/Z3815/Z3816/etc style)
    SCPI (HP5xxxx style)
    TruePosition GPS
    Trimble TSIP binary GPSDOs (like the Thunderbolt and numerous 
      "telecom" GPSDOs.
    Zyfer Nanosync 380 (19200:8:N:1)

Atomic frequency references:
   HP 5071A cesium beam oscillator
   Spectratime/Temex LPFRS rubidium 
   Spectratime SRO100/SRO70 rubidium 
   SRS PRS-10 rubidium oscillator
   Symmetricom SA22 rubidium (60 Mhz and 58.9824 MHz ref freq)
   Symmetricom X72 rubidium
   Symmetricom X99 rubidium

Clocks:
   Acron Zeit WWVB receiver
   Gravity/solid earth tide clock (uses system clock to display 
      solid earth tides and gravity offset,  Requires manual entry
      of latitude/longitude/altitude)
   No receiver, uses system clock. 

Time and frequency counters:
   Generic frequency/time interval counters
   HP531xx counters
   PICPET simple timestamping interval counter chip
   TAPR TICC time interval counter

Misc:
   Simple terminal emulator

I have received several requests for a list of devices currently supported by the v6.0 Beta of Lady Heather: GPS Receivers: Jupiter-T (aka Zodiac) Furuno GT-8031 ($PFEC commands ... not yet tested) GPSD interface (mainly a Linux thing - provides a shared read-only interface to numerous GPS devices) Motorola binary NMEA Sirf binary NVS binary (115200:8:N:1) Trimble TSIP binary receivers Trimble TAIP receivers Trimble SV6/SV8/ACE-III Trimble Accutime / Palisade receivers Ublox UBX binary Venus mixed binary / NMEA GPSDO's (GPS disciplined oscillators): Brandywine GPS-4 GPSDO DATUM STARLOC II GPSDO - inferior wannabe Thunderbolt - buggy firmware Jackson Labs LTE Lite Lucent RFTG-m GPSDO Lucent KS24361 REF0/Z3811A Z3812A NEC GPSDO ... STAR-4 compatible at 115,200 baud UCCM - Trimble / Symmetricom GPSDOs Oscilloquartz STAR-4 GPSDO (management interface) Oscilloquartz OSA-453x GPSDO SCPI - Nortel telecom GPSDOs like NTWB and NTPX in SCPI mode SCPI (Z3801A/Z3815/Z3816/etc style) SCPI (HP5xxxx style) TruePosition GPS Trimble TSIP binary GPSDOs (like the Thunderbolt and numerous "telecom" GPSDOs. Zyfer Nanosync 380 (19200:8:N:1) Atomic frequency references: HP 5071A cesium beam oscillator Spectratime/Temex LPFRS rubidium Spectratime SRO100/SRO70 rubidium SRS PRS-10 rubidium oscillator Symmetricom SA22 rubidium (60 Mhz and 58.9824 MHz ref freq) Symmetricom X72 rubidium Symmetricom X99 rubidium Clocks: Acron Zeit WWVB receiver Gravity/solid earth tide clock (uses system clock to display solid earth tides and gravity offset, Requires manual entry of latitude/longitude/altitude) No receiver, uses system clock. Time and frequency counters: Generic frequency/time interval counters HP531xx counters PICPET simple timestamping interval counter chip TAPR TICC time interval counter Misc: Simple terminal emulator