I’m starting a discussion here to get some feedback about getting an online play capable go client going.
SailGo is, in it’s current form, not really a candidate since it doesn’t account for current exchange formats.
Tsumego, on the other hand deals with SGF files and, as such, already implements data structures that might get us to, for instance online-go.com OGS interoperability. OGS has a javascript library which could probably be readily integrated in Tsumego (which is QML+JS) but OGS warns about the current state of the library.
Other things to look at: https://github.com/pzorin/qgo