A while ago, Valve has released Dota 2 for Linux systems, via Steam, after a series of testing. The game got updated again, on the 30th of July. Highlights and improvements, from the official site:

- Purchasing additional International Compendiums now properly grants all unlocked rewards
- Improved Cauldron of Xahryx and Mace of the Chosen
- Fixed bug where certain units weren’t animating
- Spirit of Atniw selection fixedThe One Horn is now Rare (was previously Common)
Minimum requirements for playing Dota 2 on Linux systems: Ubuntu 12.04 Precise Pangolin, 2.8 Ghz Dual Core CPU, 4 GB of RAM, 4 GB free space, nVidia GeForce 8600/9600GT, ATI/AMD Radeon HD2600/3600 (Graphic Drivers: nVidia 310, AMD 12.11), OpenGL 2.1 and OpenAL Compatible Sound Card.
As a reminder, you need to have the Steam client already installed, in order to play Dota 2.
If you need help the Steam installation on Ubuntu, Linux Mint or Fedora, see the following two articles.
- Instructions for installing Steam on Ubuntu / Linux Mint
- Instructions for installing Steam on Fedora