I'm running several game servers, 4 of them are Half-Life Mods:
*Counter-Strike Beta 6.1
Address: 18.104.22.168:27015Counter-Strike folder must be named "cstrk61"
The Eisbaer Mappack V2
*Counter-Strike Beta 5.2
Address: 22.214.171.124:27018Counter-Strike folder must be named "cstrk52"
*Deathmatch (Half-Life without Mod)
All servers are featuring the admin Mod, just type admin_help
in the console to see the available commands! (map voting, etc.)
A live status can be found here: www.betastrike.net/index.php?page=server-status
Server statistics for Counter-Strike are available here: www.order-of-phalanx.net/csstats.php
For more detailed information, I recommend reading the Wiki