Hello Jay,
Some of the Celestron (CPC, LCM, SLT etc ...) use exactly the same
protocol as the Merlin/Skywatcher/Panogear head.
The Nextar 's serie use different protocols !
The AllView mount, The Virtuoso Heritage Skywatcher and the Orion
Starblast serie ... all of them use also the same protocol as the
Merlin ...
The Softwares Papywizard and PandroidWiz (Android platform) are also
able to drive all that mounts ... (based on the skywatcher protocol)
The original protocol of Skywatcher has been published officially:
https://code.google.com/p/skywatcher/wiki/SkyWatcherProtocol
Claude