I have spent some time looking for a client side server monitor with gui for linux. I have worked with qstat for karamba plugin. But qstat is still command line. So I found xqf, it needs a little tailoring if your looking for any steam powered games as it defaults with quake servers.

Are you talking about a game monitor or a general server monitor for linux like cpanel?

Also, what kind of monitor are you looking for? Something that gets embedded into a web page like lgsl/qstat? HLStats also does a decent job of server monitoring. With a little hacking around, you can probably discard the player stats and only display server info.