GameTracker!

GameRanger is a free download for Mac and PC that lets you play over 600 games and demos online with friends and opponents worldwide. GameRanger offers features like profiles, friends lists, instant messaging, in-game voice communication, and competitive ladders/rankings/ratings.

Garena is a free downloadable software provided by Ocean Global Holding. Garena, short for Global Arena, is a multifunction platform that allows gamers to chat, challenge opponents, and play their favorite games online with millions of gamers world-wide.

Access to a large, and growing, library of purchasable games as well as hundreds of free-to-play games for GameFly subscribers under "Unlimited PC Play"

THE POWER OF CLOUD GAMING

Playfire is the global community for gamers. Get a killer profile, track news & discussion for your favorite games, and follow your friends progress in games.

Qtracker is an Internet/LAN game and MP3 server browser. If you want to find places to play your favorite games, look no further. You can also use Qtracker to administer your game servers, and generate HTML or PHP server listings.

Vapor is a client for installing video games made with the game engine LÖVE.

The unique place where you can keep all your games in one unified profile and create your exclusive collection

A patch that fixes adds new games and fixes a few issues with HLSW.

gamemonitoring.net is a unique tool for search and promotion of game servers. Site contains the best available server list based on user ratings. A huge list of servers with relevant information and with the voting system. This means You always receive the latest information for each server in the monitoring.

ServerBrowser.com is a browser for online game servers. Search game servers for specific countries or check servers for their players and variables.

A direct "like for like" replacement for the GameSpy MasterServer, and supports a huge number of games.333networks is the official MasterServer for several games companies, and can be self-hosted, or use the main Master, or both.