Is Basshunter Dota about the game?

The lyrics, in Swedish, are about using the voice chat program Ventrilo while playing Defense of the Ancients, a gamemode within Warcraft III: Reign of Chaos. The song incorporates samples from the game. It was released as the second single from Basshunters first album LOL.

What language is DOTA?

Scripting in Dota 2 is handled by the VScript virtual machine using the Lua programming language. Lua will be launched at run time when Dota 2 loads your add-on and can manipulate most facets of the game.