I only found this now and feel it is very well worth mentioning it here for everyone to read :)

http://www.gamespot.com/articles/gog-celebrates-six-years-of-advancing-the-drm-free/1100-6422150/

I really like the ideas they have for the future to distribute their own SDK to match players. The Galaxy client is also meant to work with slightly patched older titles, that only worked with incompatible protocols like in Settlers for example (IPX IIRC).