What are some alternatives?
When comparing DotA 2 and Quake, you can also consider the following products
Heroes of Newerth - Heroes of Newerth is a Fantastic, Action, Multiplayer Online Battle Arena, Fantasy, Strategy, and Multiplayer video game created and published by Frostburn Studios.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
League of Legends - League of Legends is an Entertaining, Action-Adventure, MOBA (Multiplayer Online Battle Arena), Online and Multiplayer video game developed and published by Riot Games.
Doom - Doom is a science fiction horror-themed first-person shooter video game in which players assume the...
Awesomenauts - Awesomenauts is a Gorgeous, Action, MOBA (Multiplayer Online Battle Arena), 2D, Platform, Sci-fi, Co-op, Single and Multiplayer video game developed and published by Ronimo Games.
Unreal Tournament - Unreal is a series of first-person shooter video games developed by Epic Games.