I've been cooking up some tools, one of them is a serverbrowser ala GameSpy. It's essentially a continuation of XQF and QSTAT which haven't been maintained since 2006 :)
On another note, I'm hosting a master-server list containing Half-Life servers on WON2 belonging to friends of mine, just add this http URL to GameSpy or XQF:
http://www.euksy.oldtimes-software.com/files/GameSpy/master

-- Marco