QStat is an open source command-line program that retrieves and displays information from game servers that have implemented a game server query protocol, such as A2S. It supports reporting information such as the state of the game server (e.g., running, down, non-response), the server name, the map name, the number of connected players, the ping response time, game server rules, and player information.
QStat comes prepackaged with a collection of built-in game types, but you can define additional game types in the QStat configuration file. By default, the QStat configuration file is called qstat.cfg, but you can specify an alternative configuration file with the QSTAT_CONFIG environment variable and the -cfg command-line option.