I'm an open source developer and community member myself and strongly in favour of open source software, and free open public protocols. As such I'm totally in favour of GOG developing Galaxy client as an open source application or open sourcing it at a later date, and I'd also be in favour of the protocols they use being open as well.
While I am in favour of that though, I do not feel that they must or even should do that nor do I have any sense of entitlement for such either (Edited: Note that in saying that, I am not implying that anyone else in particular does but there probably are people who do.) While I greatly prefer things more open than not I respect an individual developer or company's choice to develop their software in their own manner whether it is open or closed and I make no demands about it.
If we were to sit down face to face at a table over a cup of coffee to discuss this you'd find that we probably have a lot more common in thinking about such things than not, although we'll likely differ in some areas as well and that's ok too.
For the record I don't really disagree with anything you've said in your last comment above, I just don't think GOG is obligated in any way to develop their software in that manner unless they wish to do so for their own reasons and if they choose to do it in a closed development model as proprietary software and protocols, I don't see a problem with that personally even though I too would prefer to see open protocols and open source as is my general nature.
Either way I believe they're going to provide us with a nice piece of software and eventually at some point an SDK and other tools with which to interact with their services and whether it is open or not I think it is going to be a huge step forward than anything we've had before and I'm looking forward to that even if it isn't open or developed in the public eye.
Others will likely feel very differently about this for their own reasons and I can totally respect that too as I don't think there is a right or a wrong personally just different approaches and individuals have their own thoughts about these things. Nothing wrong with people sharing different viewpoints here to let GOG know their thoughts/preferences either. Ultimately they'll decide what to do and we'll end up with something one way or another. I look forward to it whatever it is, however they do it.
I apologize for the DRM comment, that was purely intended as light hearted humour and nothing more, but perhaps was out of place in the wider scope of the discussion. I have a fondness for injecting humour into things and it isn't always obvious or seen that way by others sometimes.
At any rate, under the surface I think we likely agree on more things than not to be honest.