AMXmod
Amxmod.net :: half-life scripting engine
http://www.amxmod.net/
Adminmod
Adminmod
http://www.adminmod.org/
CS-Maps
The largest collection of cs maps and css (counter-strike source) maps online, over 10,000 files for cs-maps and related downloads.
http://www.cs-maps.org/
Countermap
Countermap
http://www.countermap2.com/
HL Guard
HL Guard
http://www.thezproject.org/projects.php?pid=1
Metamod
Metamod
http://www.metamod.org/
Psycho Stats
Psychostats is web based sofware that provides comprehensive gaming statistics for players and clans on half-life or half-life 2 game servers.
http://www.psychostats.com/
Server Counter-Strike
Server Counter-Strike
http://server.counter-strike.net/
United Admins
United Admins
http://www.unitedadmins.com/