I noticed that some games have multiplayer in them is there a gog server or something??

I don't know what games you meant but I guess it's more like LAN

Depends on the game. Some games are LAN only, some games have online multiplayer if you get a CD key by asking Support.

Some games have online multiplayer, though you may need to request a CD-key for them. You would be surprised but many of these old games still have players and servers from way back.

I know what you mean.

When I was first on GOG I suggested the idea of some kind of connect forum that allowed the community to link up for multiplayer (even though I'm not really an ardent multiplayer).

There are many improvements that the GOG team could make to the forums, and to the site, (personally I'd like them to open source the site, and let us help). I think right now, and for the forseaable future they are going to be 100% on expanding the catalogue. It makes business sense, I think they've got that right (from a business perspective).

Maybe it's a good place to post GOG.com's games we can play via internet?

Edited:
Found Unreal series, still looking for other games, maybe any RTS ?

I'd be up for getting my ass handed to me in some Empire Earth, for sure.

I once tried to find MP partners via the games subforum here for a strategy game (Fantasy Wars) but nobody replied here. I would say, the natural place is in the subforums, but if there is more traffic in the General forum, why not.