Players can then watch current and recent casual matches for free, though most tournaments charge a small entry fee to view them. The Wild Card rounds from The International, however, are free, featuring some of the best players in the world. In addition, players also have a choice of multiple commentators for matches as well.
The spectator client will be upgraded in the future into a regular DOTA2 client, according to Valve, “once we expand server capacity.”
The spectator client can be downloaded from Steam here.