This class was created to query servers that use 'Source Query' protocol, for games like HL1, HL2, The Ship, SiN 1, Rag Doll Kung Fu and more.
You can find protocol specifications here: http://developer.valvesoftware.com/wiki/Server_queries
You can find easy example how to use it in Test.php
file
Open connection to a server: Connect( $IP, $Port );
Close connection: Disconnect( );
Set rcon password for future use: SetRconPassword( $RconPassword );
Execute Rcon command: Rcon( $Command );